Colossal Order and Paradox Interactive’s city builder, Cities: Skylines, turns three this weekend, on March 10. Paradox has also announced that 5 million copies have been sold on PC alone. To celebrate the anniversary and sales milestone, everyone’s getting free DLC inspired by Surviving Mars, the colony survival sim that’s due out on March 15.

The Surviving Mars DLC will contain a new radio station, Official Mars Radio; an astronaut Chirper, if you’ve not killed the bird already; and a new building, the Xchirp Launcher. Everything your city needs to get in on the space race. You could even rename one of your citizens Elon Musk and treat him terribly. I know I will. 

If Surviving Mars also tickles your fancy, Cities: Skylines owners get a 10% discount until March 30. Keep an eye out for my review next week. 

Addictive city builder Cities: Skylines is currently free to try on Steam, meaning you too could build a town where blimps blot out the sun. The free offer ends at 1 p.m. Pacific on Sunday, February 11. If you dip your toes in and decide it's worth a dive, you can also buy the game or any of its DLC for cheap through 10 a.m. Pacific Monday, February 12. 

The base game is just under $8 at 75 percent off, and the deluxe edition package is $10 at 75 percent off. If you already own the game and want the deluxe edition content (a handful of new buildings, the soundtrack and a digital art book), you can get the deluxe upgrade pack for under $3 at 75 percent off.

There are also two big ol' bundles. The $56 Cities: Skylines collection comes with all major and minor DLCs, including Natural Disasters, Green Cities and Mass Transit, as well as several content creator packs made with help from modders. Then there's the $19 new player bundle, which comes with the Natural Disasters and Snowfall DLCs. 

Cities: Skylines is pretty much the best city builder ever made, for two reasons: it's very fun to play, and reading Chris Livingston write about it is among my greatest pleasures. If you haven't picked it up yet, you can do so now for $10 as part of the new Humble Strategy Simulator Bundle. 

Although, if you have picked it up, the bundle will still be of interest. The "pay what you want" tier includes Rebuild 3: Gangs of Deadsville, SimplePlanes and Out of the Park Baseball 18. Pay above the average (which is currently $6.15) and you'll also get Mad Games Tycoon, Plague Inc and TS 2017 Train Simulator. But pay the $10 and you'll get all those in addition to Cities: Skylines.

Go forth and peruse. There's also currently an offer where every purchase nets you 10 percent off a Humble Monthly instalment, which have to date been very generous. 

The coughing citizens of your Cities: Skylines metropolis can breath again—the game's eco-friendly expansion is out now. Green Cities, which is £9.99/$12.99 on Steam and Humble Store, adds more that 350 assets to the game, from Geothermal Power Plants to Yoga Gardens and Bee Havens.

The DLC also adds new specialisations for your buildings, all of which help keep pollution at bay. You can design self-sufficient apartment blocks, for example, or plonk down shops that only sell organic and locally-produced goods.

To make sure you get your hands dirty (or clean in this case), developer Colossal Order has created three new scenarios in which you can test your green credentials, as well as four new policy options and a new monument, the 'Ultimate Recycling Plant'.

Players that don't want to pay to battle pollution get some free options courtesy of an update released at the same time as the DLC. The 1.9.0 patch adds electric cars, reworks noise pollution, introduces three new types of park (including a tropical garden) and new trees. There's the customary bug fixes, too.

You can read the full notes on the DLC and the free update in the patch notes. 

To the delight of countless smog-choked digital civilians, an eco-friendly expansion is coming to Cities: Skylines next month. The Green Cities expansion will cost $12.99 and arrive on October 19, publisher Paradox Interactive announced today. 

As previously reported, Green Cities adds 350 objects and assets to help you clean up your no-doubt horribly polluted cities, including self-sufficient buildings equipped with solar panels and rooftop gardens, sustainable power plants and spiffy little electric cars. As revealed in the announcement trailer above, there are 200 new buildings and 100 other assets in total. New visual options, more parks, and new services such as recycling are also included, along with three new scenarios and four policy options.

"Players can go completely green as the urban population grows," Paradox says,  "and create more diversified cities with new specialized options for all zones, such as a combustion engine ban in the inner city or waste filtering requirements for industrial buildings." 

As always, a free update will also accompany the expansion. This update will add a smaller selection of electric cars, road mods, beautification items like trees and parks, and changes to noise pollution. 

I haven't checked in on any of my Cities: Skylines creations lately, but last time I looked they were suffering from a number of problems, like traffic, lack of educated workers, a slight overabundance of blimps, and the fact that some idiot built a creamatorium and a garbage dump right next to a playground. Pollution, of course, is an ongoing issue in any Skylines city, but some solutions are on the way.

The next Cities: Skylines expansion will address pollution problems by letting you go green. Green Cities "adds 350 new assets to the core game, adding a massive selection of new visual options, complete with eco-friendly buildings, organic shops, electric vehicles, and new services designed to make pollution a quaint notion of the past."

We don't have a release date—the expansion only promises to arrive on the wind "later this year." We don't have a price yet either, but even if you decide not to buy it there will be the usual smattering of freebies, in this case "electric cars, road modding, changes to noise pollution, and more beautification options in the form of parks and trees, among other things." Find out more here.

From Mass Transit to Blimpton, Natural Disasters to Snowfall—Cities: Skylines has impressed with its long-term commitment to playful expansions. The latest is of the 'mini' variety, and lets players plan and promote their own city-wide music festivals. 'Concerts', as it's known, is out now. 

Said to grant players control of "every aspect of making their metropolises more musical", the Concerts add-on sees city builders erecting festival ground buildings, pricing their gigs as they best see fit, and supporting their festivities with new laws, budgets, and crowd monetisation options. 

On the Cities: Skylines modding front, changes are afoot, so say Paradox and Colossal Order: "Alongside the mini-expansion, Paradox and Colossal Order are restructuring the content manager tool as a free update to Cities: Skylines. The content manager now makes it much simpler for players to organize, search for and find their favorite mod-assets, so you can spend less time scrolling and more time building."   

Cities: Skylines Concerts is out now for £4.99/$6.99.

The Mass Transit expansion brought some new public transportation options to Cities: Skylines, but having already reported responsibly about them it's clearly time to throw a hundred blimps into the sky and see what that's like. My goal isn't just to blot out the sun with blimps, but to design a town around them. I want blimps to not only be the chief form of transportation for my citizens, but their only choice. In the new town of Blimpton, it's blimps or GTFO.

My first step is to plan my three zones: residential, commercial, and industrial. I unlock four extra squares of land (I'm playing with unlimited money and all buildings unlocked) so my buildable area looks like a giant plus sign, and I build power stations, water lines, and roads in three prongs of the plus. Not a lot of roads, mind you: I won't be needing them. But the few roads I build are long, winding, and stupid. My hopes are to discourage anyone from climbing into a car and driving: it'll just take too damn long. Want to get somewhere in New Blimpton? Better take a blimp.

A tool for renaming roads has been added to Cities: Skylines with the Mass Transit DLC, so I name my roads things like BLIMPS ARE REALLY COOL, GUYS and NO CARS ALLOWED. I figure it can't hurt. I throw in police stations, fire departments, hospitals, a cemetery, and a few other amenities. No schools, though. I want my citizens to be dumb enough to think that taking a blimp to the grocery store is a sensible idea.

I stare at the map for a bit, feeling like something is missing. Oh, right! I need to put in blimps. Heh. I build two blimp stops in each area, and connect them first with blimp lines (it dictates the path blimps will fly) and then create the blimp lines themselves. One goes from residential to commercial, one from residential to industrial, and one goes from commercial to industrial. I build blimp depots, to supply the lines with airships, crank up the vehicle count modifier to 500% (thus adding way more blimps) and boost the transportation budget to 150%. My three lines will have the maximum number of airships so there will be no excuses from my residents. I've already got 20 blimps in the air by the time the first house is built. People are moving in.

While I watch houses being built, I see a flicker of movement on one of my streets, the street I've named DRIVING IS DUMB, TAKE A BLIMP. It's a car! A car, on my street! I zoom in furiously, ready to expel the offender from my town, feeling the same way God must have felt when he looked down and saw that Adam and Eve had broken his one rule and were driving around the Garden of Eden.

It's a police car. Okay. Okay. Calm down. That's okay. The police are allowed to drive. It's not like they can fly an Anti-Crime Blimp around. Yet. Though frankly, that would be incredible. I also have to prepare myself to see other service vehicles driving on my streets, like garbage trucks, donut wagons, and hearses, because undertakers probably won't haul off the dead in dirigibles, much as I wish they would.

The residential zone quickly fills up with new homes, and I'm pleased to see a total of zero cars on the roads other than the occasional ambulance or garbage truck. My fleet of blimps drifts back and forth between stops, now around ninety airships in all. A bit puzzling, though: there are zero passengers. The people who have moved in are, much to my pleasure, unwilling to drive anywhere. But they also seem unwilling to board one of the many, many blimps that are waiting to shuttle them to the far-flung commercial and industrial zones.

To be fair, nothing has been built in the industrial zone, and while a few stores have appeared in the commercial area, they are all complaining about the lack of workers. Well, yeah, if no one is taking the blimps, no one is getting to work. 

A-ha! Staring at my blimp stats finally pays off, as I eventually see a single passenger using the blimp system! I feel like yelling "We got one!" and slamming my open palm down on the Blimp Alarm Button installed on my desk, like Annie Potts in Ghostbusters, only I don't have a Blimp Alarm Button installed on my desk. Yet.

Ninety blimps, one rider. It's a start. I click from blimp to blimp (to blimp to blimp to blimp), searching for the lone rider. I'd like to see where this brave pioneer is going. Finally, I locate the blimp he's on, which is headed for the empty industrial area. I follow it until it lands, then click on the passenger when he disembarks.

His name is Todd Harvey, an uneducated adult who works at... the blimp stop. The one he just landed at. The only person using the blimp network is a guy who works for the blimp network. It's like opening an expensive new restaurant and your only customer is the waiter. I'm a little disappointed, though Todd seems pretty stoked. As he should be, since he just rode a damn blimp.

Maybe my residents need a bit more encouragement to fly my friendly skies. After all, visiting stores no one works at isn't a draw, and with no industry there are no real jobs to commute to apart from taking tickets at a blimp stop no one visits. Maybe a little excitement is in order? Some razzle-dazzle? I quickly throw together a new district on the far end of the map and tastefully cram every goddamn specialty building the game offers into two square blocks: the giant shopping mall, the sports arena, the aquarium, the massive office towers, and so on. I add another blimp depot and three blimp stops and create new blimp lines between it and the other existing districts. Surely this will get people breathlessly clawing for some blimp rides.

It works! Instead of only Todd Harvey taking a blimp to his blimp-job, there are now a total of nine people in transit. That's a ridership increase of nearly 1000 percent, which would probably look good on a graph or PowerPoint presentation, but in truth it's still only about one rider per twelve blimps. What else could my town use?

Education, I suppose. I'd originally hoped to teach my residents using only the educational messages on the sides of my blimps, but it doesn't work that way. Instead, the blimp messages only boost the speed in which citizens can complete their education at the actual school buildings. So, I suppose I'd better build some real schools. I plop down a cluster of schools in the middle of the map, throw in some more pointlessly winding roads, add yet another blimp line to the residential area, and wait.

That's when disaster strikes.

Not a natural disaster (I've got those disabled) and not a Hindenburg disaster (blimps never explode). A car disaster. I am utterly horrified to suddenly see cars on my roads. Not service vehicles, but citizen-driven cars. They're everywhere. I'm aghast. I whirl my camera around the neighborhood, unable to believe my eyes. My precious blimps still fill the air but have been ignored by the gas-pumping, gear-shifting, double-crossing, four-wheeling heathens. You bastards.

"Fine, you want to drive?" I mutter. "I'll give you all the driving you want." As threats go, it's not a great one, like saying to someone who has asked for a pizza "You want pizza? Here are ten pizzas!" Also, it's worth noting that I'm threatening tiny computer-generated people who can't hear me. But I'm going to make driving, which is already ridiculously time consuming, even more so.

I create even longer, more-winding roads, effectively doubling drive time. It doesn't seem to matter. Driving still seems to be faster than blimping, and I think I know why. I've added so many additional blimps to the city that they're all lined up, forming what is essentially a traffic jam in the sky. Much as I love seeing blimps filling every last inch of airspace, it's just not an efficient mode of transport.

It's with great sadness I crank the vehicle modifier back down to normal levels. The extra blimps begin returning to the depot where they'll be taken into the back alley, deflated, folded up, and stored in boxes marked EXTRA BLIMPS (I'm assuming this is what you do with extra blimps).

It does seem to help a bit: the number of riders rises to almost 200, and I see more citizens queuing up at the blimp stops than ever before. Still, for a town of almost 4,000 residents, most people seem to prefer driving their cars along long, winding roads that are named with blimp-friendly phrases than actually climbing on a majestic airship. As if to signify my failure, one of the blimp depots catches fire and burns down.

My dream of a blimp-only town is dashed. I suppose people simply love their cars too much to give them up. My head was in the clouds, but their wheels are on the ground.

With the Natural Disasters expansion, Colossal Order delivered what fans had been clamoring for since day one: a way to wipe out their beloved Cities: Skylines creations with meteors, tidal waves, and tornadoes. The DLC shipped with preventative measures as well, like emergency shelters and early warning systems, but mainly it was a way for players to deliver wanton destruction upon their gleaming skyscrapers and sleepy neighborhoods (not to mention a great way to terrorize Santa Claus).

Compared to plummeting space rocks, forest fires, and deadly tsunamis, the new Mass Transit expansion initially sounded like it would be rather humdrum. You get a monorail. You get a ferry. You get cable cars and a blimp. The intention is to provide players with new ways to move their citizens around their cities and new systems to alleviate traffic jams.

My first thought was... whoopee? Look, I appreciate any addition to Skylines that gives me more options for building, but I feel like as a player I'm personally more interested in blowing up buildings with meteors than I am in peering closely at snarled intersections and drawing bus lines across the map.

Or so I thought.

Thing is, I'm having more fun with Mass Transit than I did with Natural Disasters (or Snowfall, or After Dark, for that matter). Yes, explosions and fires and smoking craters are cool, but the enjoyment is a bit fleeting and when I'm working on building up a city the last thing I want is to deal with a tornado. (Once I'm done with the city, sure, let's destroy it just for fun).

And it's not even the new transit options themselves that makes the expansion so enjoyable. Having new monorails and commuter blimps and ferries is nice, but the real fun of Mass Transit, I'm finding, is coming from the incredibly useful hub buildings. While you can create simple stops for your new transit vehicles, the satisfaction comes from linking them together at the new and expansive hub terminals. To put it simply: the transit hubs are great. If Natural Disasters inspired you to knock down your city, then Mass Transit will make you want to rebuild it from the ground up around these new hubs.

If you have a ferry shipping commuters across a bay, for example, you can deliver them to a hub where they can climb aboard any number of different bus lines that you've linked to the terminal. The buses can then bring them to another hub where they can climb aboard a monorail. There are hubs that act as exchanges from metro lines to trains and even make connections from buses to blimps.

As someone who has never been interested in seriously delving into traffic problems in Cities: Skylines—typically I just slap some extra roads around, or replace two-lane boulevards with something wider—I'm finally and genuinely enjoying focusing on solving my traffic woes. I can't even say why it's so enjoyable, really, but after adding a ferry to get commuters across the bay, and then dragging all my bus lines into nice orderly stops at the ferry terminal, and then seeing citizens immediately get in line because seriously anything is better than trying to drive through my city—and I should know because I tried it myself once—it's just a remarkably satisfying activity.

With some well-placed interconnected terminals, your citizens will be able to step out of their homes, get on a bus or a metro, and make their way across your entire city without ever getting into their cars or even having to walk far to reach their next connection. I've been busily plopping in hubs, spending lots of time linking them up, and then happily watching the results. 

In fact, I'm so into it that I'm completely razing skyscrapers and deleting parks and wiping out neighborhoods, simply because I want to get all my new hubs up and running. In that respect, I'm almost acting as my own natural disaster, and sure, I see a lot of sad faces when I tear a park down or delete a university, but no one complains when I use the space to build a complex network of public transportation. At least, they don't complain loud enough for me to notice.

There's more to the DLC than just the new hubs and rides, like wider highways, roads with monorail tracks built in, and even roads with asymmetrical lanes: two lanes in one direction, and one lane in the other, useful if you've got a traffic problem heading in one direction but not the other. 

There's a few new policies, too, such as adding educational messages to blimps—as opposed to blinking advertisements—and you can also rename roads by simply clicking on them now, which is an addition based on a popular mod. And, you can zoom down to intersections to add and remove stop signs and traffic signals with a simple click, which lets you tackle traffic issues without doing a whole lot of additional construction.

I'm a little surprised to be quite so taken with what I thought would be a useful addition to Cities: Skylines if not a particularly exciting one. And I definitely wouldn't have expected to enjoy linking bus lines to ferry terminals more than I like calling in meteor strikes on football stadiums. But here we are. I'm genuinely excited about bus lines and blimp stops and ferry terminals. There's a first time for everything.

On May 18 the Cities: Skylines gets more syklines in the Mass Transit expansion. Monorails, cable-cars, ferries and blimps are included in the $12.99 / £9.99 pack, which also adds new types of landmarks, and roads, and massive transport hubs to link all these things together. No mention of an Elon Musk style Hyperloop yet, though.

The update also includes new scenarios that challenge you to solve traffic problems. "Become an expert in traffic flow," says the blurb on the official Mass Transit update page, "use that knowledge to improve your city!" There are also new hats for Chirper the definitely-not-Twitter social media bird.

Cities: Skylines seems to have successfully nicked SimCity's biscuits, selling 3.5 million copies as of March.