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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RSS feed Articles

We have finally opened our website where updated content will be posted two to five times a week. If you wish to track our detailed progress, simply visit regularly or subscribe to our RSS feed. If you have any inquiries, suggestions, or feedback, let us know by using our contact form at .

All details about Sierra Ops' release date for both demo and full version will be set on our milestones page . There is also an active Status Report page which updates the numbers automatically whenever we finish a single asset.

Here are our new backgrounds:

Game system
- 75%
- Working OP:SD Game System migration, hp/shield bars, EN Allocation
- Working Dev/Mission Screen functionality
- Working VN feature
- Bug Fixes

Script - 90%
- 19,108 words for common route
- Estimate of complete version including branching - 25,000 words

Artworks - 67.5%
- 3/20 stage backgrounds + 3 in progress
- 2/10 Ship Interior + 2 in progress
- 2/12 CGs
- 10/10 UI, Animation in Progress
- 20/20 Ship/Platforms/Weapons Assets, Animation in Progress
- 5/20 Particle Effects
- Normal maps for environmental lighting effects on all ships - finished!

Music - 80%
- , Operation SD: Space Defense playlist

When we post our next news article, it will be about the Alpha or Demo Release. We're hoping to receive more feedback so we can make Sierra Ops the best we can.

If you wish to support us, simply purchase the first version of the game, Operation SD: Space Defense if you haven't, or more simply, share our rebuild plan to your friends or relatives. The full game page of Operation SD: Space Defense including its downloads will be changed totally to the rebuild version as soon as it's completed, so the previous version of the game will most probably be overwritten entirely.

Thank you for taking your time in reading, and have a pleasant day!

Operation SD: Space Defense Rebuild Progress

Operation SD: Space Defense Rebuild Progress

2 years ago News 2 comments

"Sierra Ops" is the new title of our old release, Operation SD: Space Defense. It will contain new features such as discussion and briefing cut scenes...

Operation SD: Space Defense Released on Desura

Operation SD: Space Defense Released on Desura

3 years ago News 0 comments

Thrust into mankind's first interplanetary war between the Earth Alliance and the Ares Confederation.

Tips and Tricks

Tips and Tricks

3 years ago Feature 0 comments

If you're having a problem finishing a stage in Operation SD, just remember the following general tips and tricks.

RSS feed Downloads
Operation SD (demo)

Operation SD (demo)

3 years ago 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 says:

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

+2 votes     reply to comment
Kalus Creator
Kalus Apr 29 2012 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 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 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 replied:

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

+2 votes   reply to comment
Dasaki Apr 16 2012 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 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 replied:

Thanks, we'll keep that suggestion in mind.

+2 votes   reply to comment
Dasaki Apr 17 2012 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 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 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 by stygma1982

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Operation SD: Space Defense
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