Set in the year SE 3256, the player is thrust into mankind's first interplanetary war between the Earth Alliance and the Ares Confederation. As the promising captain of the experimental dreadnought prototype, codenamed Sierra. Your sole objective is to help turn the tides of the war, utilizing the ship's advanced combat systems, flexible energy allocation and optimized platform deployment capabilities. To the captain, the core principles of prudence, guile, resource management and patience are essential to survival. The technology incorporated in Sierra allows it to explore multiple paths to victory: evade and assault enemy ships in classic broadside warfare; research armaments and upgrades to outgun the enemy fleet; or outnumber them with remotely-controlled weapon platforms. Rout the enemy’s armada in order to quell the rebellion and save Earth from the corrupt colonials.

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2 comments by Kalus on Jan 21st, 2014

So here we present to you, the build that you've been waiting for: It is now designed to let you play the game continuously and is now a lot easier to understand how Sierra Ops is played - hopefully!

PC :
Direct Link -

Mac :
Direct Link -

Linux :
Direct Link -

Mediafire Folder:

Known issues:

  • Sometimes, you can't enter the Resupply Station. So what you should do is simply enter the LITE simulation, and escape right away, and then return to the station.
  • The free camera mode sometimes has issues with the platform mode, making it hide the mouse cursor. The solution is to just alt+tab back to the game to regain control of the mouse.
  • The Mac/Linux release hasn't been tested thoroughly, as well as Win8. Volunteers are very welcome to try the game, and report the problems to us by sending an email to
  • The pause/battle menu is just a placeholder, but the window/full screen mode button there works.

Additional Information:

  • The Harbinger cannon requires Level 20 weapon and Level 20 Particle Capacity.
  • The abilities in game uses the shortcut keys E,R,T, but you need to learn the appropriate skill for it in order for them to work.
  • We've also made the Leviathan more active and has a second mode at 30% hp and below. If you can record your battle with the Leviathan and has managed to defeat it, the first three people to upload at Youtube will win an all digital bundle! (It's the 80$ perk at our IndieGogo, containing exclusive digital works such as the game design book, HD wallpapers and Original Soundtrack - )
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Operation SD (demo)

Operation SD (demo)

Mar 28, 2012 Demo 1 comment

Press "read more" for instructions on how to play the game.

Post comment Comments  (20 - 30 of 57)
cybersleuth58 Nov 27 2012, 2:22pm says:

I cannot get it to run. First I get the error there is no suitable graphics card. Then it tells me it requires pixel shader and (I am blanking). Then it crashes. Any ideas?

+2 votes     reply to comment
Kalus Creator
Kalus Nov 28 2012, 7:02am replied:

Hmm, can you tell me what is your video card? This error usually happens if the video card of your current setup does not have at least pixel shader 2.0. ( A requirement of the XNA framework)

+2 votes   reply to comment
dickheadstrong Jun 17 2012, 3:40am says:

I am trying to play demo version. I only get blank screens during tutorials (with "Next" or "End Tutorial" button on lower right of screen). I can't find any other instructions or even get to the options to set up the controls. If I could find that at least I'd know what controls/commands I'm supposed to have.

+2 votes     reply to comment
Kalus Creator
Kalus Jun 17 2012, 11:48pm replied:

That's odd, the tutorials are supposed to be video encoded in wmv format. The reason why you're getting blank screens is probably a video codec problem of some sort. Try updating your windows media player/video codecs to see if it helps. The controls are fixed so you unfortunately can't set up the controls. Other than that, you can try to play the tutorials inside the Content/Transitions folder on your favorite media player its numbered sequentially so you should have no problems. If all else fails I can give you a rundown of the controls in text format.

Hope it helps.

+2 votes   reply to comment
dickheadstrong Jun 24 2012, 1:08am replied:

Thanks for the help. I'll try opening the vid's with Zoom Plyr. Are the controls fixed on the full game too? Or just the Demo?
Don't worry about answering right away. Just got the original Deus Ex ($2.49 on Steam this wkend only).
Just wanted U to know that your Human (I'm assuming) response/interaction is greatly appreciated. IIf half of the games on desura are equally supported, I'll be buying a lot more games here instead of steam. (I AM cheap. I mostly buy games < $5 or $10, so it's not a big win 4 U.)
But Thanks, Anyway.

+2 votes     reply to comment
Kalus Creator
Kalus Jun 25 2012, 12:58am replied:

The controls are fixed in the full version too.

+2 votes   reply to comment
Crusender May 2 2012, 3:24am says:

me i have some kind of bug whit desura... i can install demo, i can launch it and play it no problem. I buy the game, uninstall the demo, Install the full version, launch it, then a error appear that say go to error file for see the error but the file it is empty. So i download the installer, install it and work fine, but desura one still not working....

+2 votes     reply to comment
Kalus Creator
Kalus May 2 2012, 4:19am replied:

Just to clarify things is the version of the game on desura 1.0b? Also, which error file did you opened? the one located in the mydocuments or the one located in the content folder?

+2 votes   reply to comment
Crusender May 2 2012, 3:03pm replied:

empty one was game folder, i find the one in my document just said, the error look like it missing the shipdata file in my document. look like when installing via desura it dont install shipdatafile in mydocument.

+2 votes     reply to comment
Kalus Creator
Kalus May 2 2012, 10:31pm replied:

Its probably because the savedata folder in the mydocuments doesn't contain the shipdatafile but has the folder itself. I have just tested it now deleting the whole savedata folder should resolve this problem.

+2 votes   reply to comment
Crusender May 3 2012, 5:28am replied:

it work, thx for the help

+2 votes     reply to comment
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Operation SD: Space Defense
Developer & Publisher
InnoMen Productions
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Release Date
Released Apr 5, 2012
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21 votes submitted.

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Highest Rated (2 agree) 10/10


2,29 € Only? + 2 12/10

Apr 10 2012, 3:21pm by stygma1982

Tactical Shooter
Single Player
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