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  (30 - 40 of 57)
deathisnear Apr 29 2012, 1:16pm says:

my mission progress wasnt saved however my ship was, any explanation?

+2 votes     reply to comment
Kalus Creator
Kalus Apr 29 2012, 11:34pm replied:

Sorry about that, thanks for pointing it out. I can't believe I let such an obvious bug slipped up. I'll have this fix as soon as possible.

+2 votes   reply to comment
Kalus Creator
Kalus May 2 2012, 3:13am replied:

Update: Sorry for the delay. The patch is up now, it should fix the stage data from not saving properly.

+2 votes   reply to comment
Aarkreinsil Apr 17 2012, 4:39pm says:

Is this still in development? As in, content patches and/or expansions coming up?

+2 votes     reply to comment
shr0ud Creator
shr0ud Apr 17 2012, 9:00pm replied:

This game is going to be as is. We're planning sequels, though.

+2 votes   reply to comment
Dasaki Apr 16 2012, 6:16pm says:

I feel like there should be Mecha in this game, lol. I think it's the music from the video, and how the game looks. Gundams? lol

looks good, I might get it.

+5 votes     reply to comment
stinkytaco Apr 15 2012, 2:06pm says:

VEry consistant artwork! Like the music too. reminds me of an old Konami SNES game.

Only suggestion so far would be animating the chat avitars

+3 votes     reply to comment
Kalus Creator
Kalus Apr 15 2012, 11:42pm replied:

Thanks, we'll keep that suggestion in mind.

+2 votes   reply to comment
Dasaki Apr 17 2012, 7:16pm replied:

I'd also like to see animated chat avatars. give the game more of a Star Fox feel to it.

+3 votes     reply to comment
Kalus Creator
Kalus Apr 20 2012, 11:15pm replied:

I knew I should have insisted on that. hahaha XD We'll definitely put that feature next time.

+2 votes   reply to comment
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Operation SD: Space Defense
Developer & Publisher
InnoMen Productions
Custom Built
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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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1 year ago
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