Thousands of alien machines are descending on Earth's first interstellar colony in this massive-scale new tower defense game from the publisher of Ashes of the Singularity and Sins of a Solar Empire: Rebellion.
All Reviews:
Mostly Positive (47) - 72% of the 47 user reviews for this game are positive.
Release Date:
Apr 16, 2019

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Early Access Game

Get instant access and start playing; get involved with this game as it develops.

Note: This Early Access game is not complete and may or may not change further. If you are not excited to play this game in its current state, then you should wait to see if the game progresses further in development. Learn more

What the developers have to say:

Why Early Access?

“Feedback and testing are critical for game development. We are constantly iterating and trying out new ideas and we need players to help us through that process in order to deliver the best game possible at release.”

Approximately how long will this game be in Early Access?

“Siege of Centauri is well on its way to completion, but it still needs time for polish and iteration. We want to be able to have the opportunity to weigh player feedback and make changes based on that as well. Our goal is to release the game in the Summer of 2019.”

How is the full version planned to differ from the Early Access version?

“Right now, we only have a select number of missions and maps available. By the time the game releases, we will have full campaigns and a large set of maps, complete with voice acting, graphics, and other additional game polish. We will introduce new mechanics, bug fixes, and further iteration on the game throughout the Early Access period.”

What is the current state of the Early Access version?

“Currently, players have access to the campaign mode, with survival mode coming later. As development continues, we will add more missions into the campaigns, new terrain types, and new enemy types. Leaderboards and rankings are also on the way, along with additional polish through bug fixes and iteration, the addition of voice acting and cinematics, and modding tools.”

Will the game be priced differently during and after Early Access?

“After Early Access, the price may gradually raise as more features and content are added in. We have not finalized the price for release.”

How are you planning on involving the Community in your development process?

“Community is so important to us, which is why we choose to offer Early Access. We need your feedback on balance, wishlists for future content, and bug reports. Most of all, we want you to tell us what parts of the game you’re having fun with - and also, what you’re not. We actively read the forums on Steam.”
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Recent updates View all (6)

May 16

Siege of Centauri: Early Access Version 5 Now Available

Thank you all for your feedback. We are listening and have made some significant changes to the game based on it. Most notably we redid the entire game progression to be smoother. That requires redoing all the maps so we couldn't release new missions as they wouldn't fit in with the old system.

The big change is that we will no longer tie unlocks to score. Instead new towers and orbital abilities will be unlocked by completing missions. This offers us a few advantages.


  • New Progression System- Tower/orbital unlocks are no longer tied to score. Instead they are unlocked by completing missions. Because of this unlocked tower/orbital popups will no longer interrupt game play and we can have more score variety (it was difficult to balance people unlocking towers in time if someone got a lot less points than a another player because they were playing on a lower difficulty level).
  • Chronoshift- This replaces the pause mechanic. Pausing now puts the game into "bullet-time" or "matrix" mode where the player can slow down the action to make decisions. But this is a limited resource to keep the pressure on game play. On easier difficult levels we are generous with the time given, but on higher difficulty levels it will be tougher.
  • Outposts- Some maps have Outposts. These are buildings with no military value, but they give a big score bonus if they survive the mission. It's up to you if you want to spend resources defending them or not.
  • New Mission: Dule. A large map with multiple choke points and a defensible colony, and hard to defend outposts.
  • New Mission: Ascent. A mountain with the colony on top and winding paths going higher and higher until they reach the top.

  • There are now 9 difficulty levels.
    • Trainee- -90% Score, +60% tower damages, +100 metal,/n Infinite Chronoshift
    • Beginner- -75% Score, +50% tower damage, +50 metal,/n Chronoshift depletes 75% slower
    • Novice- -50% Score, +40% tower damage,/n Chronoshift depletes 50% slower
    • Easy- -25% Score, +20% tower damage
    • Normal- No Score Modifier, Normal hit points
    • Challenging- +25% Score, +30% enemy hit points
    • Hard- +50% Score, +60% enemy hit points,/n Chronoshift replenishes 50% slower
    • Unyielding- +75% Score, +100% enemy hit points,/n Chronoshift replenishes 75% slower
    • Nightmare- +100% Score, +150% enemy hit points,/n Chronoshift never replenishes
  • Decoy no longer lasts forever.
  • Increased the cost of drone bays.
  • Rail Gun delay between firing increased slightly.

  • Minimaps give an audio and visual queue whenever a new wave starts, telling you exactly where they are coming from.
  • Buildings with hit points (metal refineries, fission reactors, etc) now show their hit points when selected.
  • Towers and orbitals now have a highlight ring if they are available.
  • UI Animates when a mission starts.
  • New splash screens images, new campaign screen image.
  • Replaced all the unit and tower selection images.
  • New/updated sfx.

  • Fixed an issue where a tower can stick to a lower tier unit when there is a better target in range.
  • Fixed an issue where Scarabs couldn't attack.
  • Fixed an issue where Punishers smoked when undamaged instead of when they were damaged.

6 comments Read more

May 7

New Towers, new progression, UI updates and more!

Greetings! We've gotten so much terrific feedback on the recent beta updates that we're going to use this week to focus on implementing your suggestions. This means there won't be any map updates this week.

Last week we added the tower positioning grid which was, by far, the #1 request from players.

Here is a preview of what's in store for next week:

  • Time Dilation. You can still his ESC and take stock in the situation on the map. The new Time Dialation feature lets you hit SPACEBAR and it slows the game to an utter crawl so you can place towers and react to what's happening. But it's a finite resource (right now, it's super generous and the difficulty level will affect how much of this you get).
  • 10 difficulty levels. Players will be able to tick the difficulty one way or the other with far more granularity.
  • 3 new maps.
  • A new progression system. Instead of score unlocking the progression the mission will unlock the new towers at the start so that you can be introduced to them more gradually. The progression was the #2 request we focus on to help gradually introduce players to the enemies and different towers. Plus, once you have the tower, you can go back to a previous map to amp up your score.
  • A couple of new orbital abilities and new towers.
  • Outposts. These are places you have colonists living. You don't have to save them to finish the level but saving them gives you more points.
  • Updated Audio tracks. Riku, who did most of the music for Star Control II and Star Control: Origins has joined us on Siege of Centauri and his music will start to show up.
  • New sound effects. Mason's new sound effects should start to show up.

We are also working on a DirectX 12 version of the game that should further improve performance, even on "lower end" hardware.

Similarly, balance continues to be a focus as we make changes to the maps, progression and map designs.

Since this is a beta, we are trying to take more steps to make sure new players understand that this isn't a demo. The point is to listen to player feedback and put their ideas into the game.

Once we are satisfied with the pacing and balance, we'll start recording the voice overs and unspool the story elements that give you a background on who the Substrate are and why they are attacking humanity's first interstellar colony.

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About This Game

Siege of Centauri puts you in command of the defense of Earth's first interstellar colony. Thousands of alien machines are descending on the helpless colony and only you, with your arsenal of fast-deployed orbital defense structures (FODS) can stop them.

The enemy comes in all shapes and sizes, challenging you to counter them with the right defense in the right place. Siege of Centauri combines the best elements of classic tower defense games with the strategic depth Stardock has delivered in past titles, including Sins of a Solar Empire: Rebellion and Ashes of the Singularity.

Battle across the surface of an alien world through a series of story-driven campaigns or fight for survival in a doomed region to see how your skills match up against thousands of other players across the world.

System Requirements

    • Requires a 64-bit processor and operating system
    • OS: 64-bit Windows 10 / 8.1 / 7
    • Processor: Quad-core Intel / AMD Processor
    • Memory: 6 GB RAM
    • Graphics: 2 GB GDDR5 NVidia GeForce 660 / AMD R7 360 or better
    • DirectX: Version 11
    • Storage: 10 GB available space
    • Sound Card: DirectX Compatible Sound Card
    • Additional Notes: 1920x1080 Display Resolution or Higher; additional disk space will be required during Early Access
    • Requires a 64-bit processor and operating system
    • OS: 64-bit Windows 10 / 8.1 / 7
    • Processor: Intel Core i5 or Equivalent
    • Memory: 8 GB RAM
    • Graphics: 4 GB GDDR5 NVidia GTX 970 / AMD R9 390 or better
    • DirectX: Version 11
    • Storage: 10 GB available space
    • Sound Card: DirectX Compatible Sound Card
    • Additional Notes: 1920x1080 Display Resolution or Higher

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