It's the gifs which made me fall in love with Opus Magnum. Without them it's reliably good Zach Barth fare—an alchemy-themed option from his assembly line programming puzzle oeuvre where you move different reagents around a board in order to create compounds. With them it's a puzzle game which has the capacity to take hours of concentrated, messy tinkering and present it back to you as an elegant, perfectly looping mechanical process.

Here's how it works. The actual puzzle-solving element of Opus Magnum tasks you with creating a particular compound as a finished product. Compounds look like 2D molecules. For example, face powder is one hex tile of Elemental Earth joined by an alchemical bond to an adjoining hex tile of Neutral Salt. 

Getting the Elemental Earth is quite easy because it's the basic reagent the level starts you off with. Just pick that up using one of the mechanical grabber arms and move it around. Getting the Neutral Salt requires you to use a grabber arm to pick up a bit of Elemental Earth and pass it over a hex tile called a Glyph of Calcification. 

Once you've done that you need to drop both the Salt and the Earth in the two adjoining empty hexes which make up a tile called the Glyph of Bonding. This fuses the bits together to create the face powder. After that you pick up the face powder and move it to the product section. 

The product section is a tile in the exact shape of the compound you're creating. It acts as a guide so you can see how the elements need to connect, but is also part of the puzzle as your alchemical products are only counted if they are placed exactly on the product tiles.

So going from one tile which spits out Elemental Earth to a bonded pair in a collection slot via one transmutation is a bit of a palaver. My solution used piston arms, a Glyph of Bonding, one of Calcification and a whole heap of retractions, rotations, grabs and releases.

I lost track of the minutes as I repositioned tiles, or ran the programming instructions to check for errors. I frequently mistook the rotation command for the pivot command. If you do that, the element an arm is holding uses the end of the arm as a pivot point, instead of rotating around the tile the arm extends from. I forgot to use the reset command at the end of a line and wondered why it wasn't periodically repeating properly. 

If the game packaged up footage of all the steps I'd taken on my way to a solution it would have been a horrific mess. If you watched it you would think less of me, not only as an alchemist, but as a human being. It would be a Logic Game Crime. 

Making records

What the game actually does is run the program long enough to collect a number of products, and thus presumably check that you have not botched a solution which just about holds together for a single run. It then takes one loop of this solution and gives you the option to record it as a gif. 

The advantage of these gifs to Zachtronics is obvious—they form a wonderfully shareable showcase of the game, tapping into the same hypnotic appeal as the real life machinery footage over on the mechanical gifs subreddit. 

But the value for the player is more unexpected. Sure, it acts as a trophy; a way of showing off an odd or cool contraption to your friends. But it also performs another function. With programming puzzle games like this, you can bash your head against them for hours on end, making tiny changes, fixing problems and revamping entire segments. While you work on them they can feel messy, frustrating, unwieldy. 

Then you finish and you get the gif. It separates the period of strife from the solution. I've used the word ‘elegant' to describe these gifs a few times and I think it helps convey how they look in this isolated state when you've tried to refine the systems and have accomplished the objective. 

These gifs wash away the stress and frustration of the puzzle and convert the solution into something enjoyable in its own right. The kind of puzzle-solving Zachtronics games offer stresses me out. But here the gifs act as a counterweight. They soothe and they celebrate, minimising the memory of frustration and replacing it with triumph.

Update: After failing GOG's idiosyncratic internal curation system earlier this year, Zachtronics' Opus Magnum was denied access to the CD Projekt-owned digital storefront. As outlined in our original story below, the process appeared as confusing as it did complicated—particularly given the quality of the game in question. 

Now, GOG has reversed its decision. "We did it! You did it! And then we did it! It's good to finally have the brilliant-yet-approachable Opus Magnum," reads this tweet, before pointing those interested towards the game's newly-launched store page and a limited-time ten percent discount. 

When quizzed about its U-turn, GOG followed up by saying that despite its curation process, it does take what its community wants into consideration with every decision. 

Another tweet reads: "The game's outstanding quality and community demand speak loudly and clearly—we're human, we're not infallible, but we're also not immovable. It's great that we get to listen, reevaluate, and bring Opus Magnum's to our catalog in the end—it's every bit worth it."

Our original story follows.

Original story: 

Opus Magnum, the latest puzzle game from Zach 'Zachtronics' Barth, received one of our highest review scores in 2017. Alex gave it a 91, calling it "one of the very best puzzle games of the year, if not the decade." It's somewhat surprising, then, that it was rejected by game distributor GOG. 

In a recent tweet, Barth shared a statement sent by GOG, which explains that Opus Magnum hasn't appeared on the storefront because it "did not pass [GOG's] internal curation system." Further explaining its position, GOG wrote: 

"We take into consideration many other factors than just the actual game itself—the reviews we provide for example do not review the game in general; so like an objective game review like on PC Gamer or what not—but we do it from the angle of our entire user-base." 

I reached out to GOG for clarification, and the company confirmed the statement Barth posted is legitimate, adding that they "don't want to comment further on it." 

Opus Magnum's rejection sparked a debate around how videogame storefronts are curated, with Steam's much-maligned Direct program serving as a counterpoint. Naturally, some backed up Opus Magnum, while others argued that missing a gem or two is a small price to pay for weeding out the sort of shovelware that routinely clogs Steam's new release page.

If you've never heard of Opus Magnum then you should definitely read Bruno's excellent piece about why it's impossible, and why that's okay. It's a complex puzzle game about alchemy in which you construct mechanisms to turn atoms or molecules into whatever it is you're trying to produce to advance the story. It's getting rave reviews on Steam and I haven't heard anyone say a bad word about it.

If it sounds familiar then that's probably because you've seen a gif of it on Reddit or Twitter: watching those miniature machines swivel and twirl is immensely satisfying (again, there's plenty to watch in the article linked in the previous paragraph), and at the end of each puzzle the game encourages you to share your clips.

It comes with a story-driven campaign, a puzzle editor and Steam Workshop support. Anyway, the motivation behind this post is that it's just left Early Access after two months of player feedback, and you an pick it up with a 10% discount on Steam, where it costs £13.94/$17.99.

It's Steam only for now—GOG didn't fancy selling it because it "looks too much like a mobile game", developer Zachtronics said on Twitter. That seems a rather strange decision.

If you enjoyed Zachtronics' previous games, including Infinifactory and SpaceChem, then it's definitely worth considering.

It seems almost inappropriate to call Zachtronics’ Opus Magnum a puzzle game. I tend to think of it as a problem-solving game, or an engineering game. Its ethos—gentle, forgiving, gradualist, concerned with incremental improvement rather than strokes of genius—is at odds with most of the puzzle games I’ve played. 

It came to my attention first through the stunning looping gifs it produces: flat little worlds of constantly moving machinery, reminiscent of the atomic-level manipulation of SpaceChem. I don’t normally play a lot of puzzle games. I’m fond of tiny PuzzleScript experiences, and I’ll play puzzle platformers like Fez and first-person games like The Witness, but I’m not an enthusiast of the genre. I suspect I’m not alone in loving Opus Magnum in spite of my cooler reaction to puzzles in general, though.

It achieves something beyond what a game like The Witness tries to achieve. Something, I’d argue, more fertile and appealing than the maze-filling in that game, or the convolutions of Fez. Opus Magnum is less about breaking through frustration and more about steadily building up to something—less about getting into the designer’s head and more about expressing your own way of thinking.

How to turn lead into gold

Every level in Opus Magnum is a simple problem of alchemy. You have inputs ("atoms" or "molecules" of fundamental elements such as earth, salt, or gold), and expected outputs. Your goal is to assemble mechanisms and program their actions so that they transmute inputs into outputs.

As the game’s story progresses, the player is tasked with manufacturing everything from fuel for alchemical airships to poisonous lipstick. It’s clear at every point that, while there’s a difficulty curve, the puzzles are very much designed around the story—they stem from narrative ideas, rather than purely mechanical exploration of the design space. 

Most puzzle games can’t do that, because they need to very carefully and deliberately ramp up their difficulty. They have to make use of every nook and cranny of possibility in a mechanic before moving on to the next one. Opus Magnum is broad and open-ended in a way that lends itself to this kind of structure, though. It doesn’t have to wring every bit of value out of its mechanics.

Like a lot of puzzles, they break down into smaller problems. The difference is that those parts are completely independent—once you’ve solved a subset of the problem, you know that solution works and it just has to be joined to the rest. Finishing a level isn’t a matter of finding a solution but triangulating your way towards one. It’s climbing a mountain, not leaping across a gorge.

A lot of puzzle games let the player make mistakes that only become apparent later, sometimes requiring the entire solution to be scrapped. Even the solitaire puzzle that accompanies Opus Magnum, Sigmar’s Garden, is like this, as are countless other puzzle games. Different parts of the solution interfere with one another, gradually constraining how the puzzle can be solved so that only one solution is valid at the end—think of how every square in Sudoku has to exist in agreement with every other square.

A tiny but incredibly effective example of this interdependence is PrograMaze, a mindbending PuzzleScript game. PuzzleScript is designed for tile-based puzzles and Sokoban variants, and PrograMaze presents the simplest possible problem in this space: move a blue tile to the orange goal. The difficulty comes from how you control the tile by writing a simple program, and the bits of memory that your program lives in are also the space that the tile moves through. 

Essentially, you have to build a maze that also expresses a path to solving itself. It’s a game entirely about the player getting in their own way, which to me distills the quality puzzle games sometimes have that gets them called fiendish, twisted, or cruel. There’s a meanness to making the player their own villain—it's hard to execute well, and not for everyone.

Opus Magnum avoids this completely. It doesn’t want you to get in your own way, and it doesn’t want its problems to feel like mean-spirited tricks. It never hides something in its levels meant to elude your attention until you find it halfway through, invalidating your tentative solution.

Because solutions are assembled from parts that can be built independently and compartmentalized from one another, you can start from either end of the problem, or you can complete different sections independently and integrate them at the end. The more complex a level, the more angles of attack you have to start solving it. The most daunting levels in Opus Magnum act as invitations—you might not be able to see the whole solution at once, but you can see how you could do a part of it. And once that subset is done, what remains is less complex.

A friendlier brainteaser

Most of all, this is a forgiving game. You always have unlimited space and resources to assemble your solution, limited only by your inputs. It ensures that mechanisms stay in sync as they cycle through the solution you’ve assembled. Letting an atom linger in place after being transmuted won’t cause it to turn into something else entirely. Opus Magnum never demands an efficient solution, never demands you prove you’re good enough before letting you advance.

The designers clearly realize most of the joy in Opus Magnum comes from optimization, and so they’ve built a game in which finding an initial, crude solution is easy. Taking a crude solution and making it faster, more efficient, more compact, and more elegant, is a pleasure absent from most puzzle games. There’s a comfort in knowing at that point that you can’t fail. You’ve already found your answer, you’re just seeing if you can make it better. 

Opus Magnum explicitly encourages you to optimize size, cost, and speed with its histograms. These histograms are so much smarter than a leaderboard. Instead of asking "Can you be number one?" a fundamentally boring question to which the answer is almost always no, they ask, "Can you make it to the 70th percentile? The 90th?"

They all but ensure players will have something to feel good about with every solution. Invariably, you’ll be operating either faster, cheaper, or smaller than most other players, simply by virtue of how those three properties are at odds with each other.

Making your machine faster entails adding more components to it, which increases its size and cost. Making it smaller and cheaper means making it slower. And often the very cheapest machines need extra room to work, particularly as the levels get more complex. Every solution has to fall somewhere within this triangle. Perfectly optimal solutions that hit all three targets don’t exist for any but the most trivial problems, making optimization a matter of personal style. Some players will tend towards "tall" solutions with numerous devices working in unison at fast speeds, other might go for "deep" solutions in which small numbers of devices perform long, complex programs.

And there’s a hidden, third optimization that can’t be quantified in a histogram but is also very much encouraged by the game: aesthetics. All Opus Magnum solutions are visually satisfying, as illustrated by the mesmerizing looping gifs they produce. But some solutions are more elegant, more beautiful than others. Opus Magnum revels in its machine dance. Building a good-looking construct is its own reward.

Zachtronics games have always stood slightly apart in this way, but Opus Magnum takes this philosophy of design and runs with it. There are no tight constraints like the limited board and code space of Shenzhen I/O, no room for messing yourself up like the finicky integration of SpaceChem. Perfection is unattainable but you have the room to build whatever you want. Opus Magnum is a puzzle game that you play rather than stare at in frustration. 

Many puzzle games have built-in puzzle or level editors, but Opus Magnum is the only one I’ve played where you can use that functionality to entertain yourself. It’s problems aren’t created by working backwards from a solution—you can pose a question you don’t already know the answer to. Rather than the tightly prescriptive jumps of Super Meat Boy, it’s the open-ended parkour of Mirror’s Edge, where vast spaces of play open up from almost any starting condition and true surprise is possible.

While a good puzzle feels like a duel between designer and player, Opus Magnum is much more like a conversation. It’s posing a question not because it wants to see whether you’ll get the answer right, but because it’s genuinely interested in what you have to say.