Development on it lasted from March 2006 to February 2008. It was first revealed to the public in May 2007 as a then-untitled military game with only a few screenshots accompanying it in the Croatian game magazine GamePlay. It was supposed to ship in 2009 but was canceled by Atari after the pre-production cycle, resulting in the layoffs of several Croteam employees.
T.E.O.R appears to be a somewhat realistic FPS game developed by Croteam for the now-defunct game publisher Gamecock. How the actual gameplay would work is unknown, as the game was canceled before details were released. A tank appeared in a screenshot, hinting that vehicles were to play a role, even if they were just NPCs.
Screenshots show that the game would take place in modern-day Somalia, as depicted by the destroyed Middle-Eastern buildings in the handful of screenshots released. There would also be a ruined office building somewhere in the game.
A magazine article that unveiled Serious Engine 3 showed off several weapons for the then-unnamed game.
In addition, some unused animations for a model in Serious Sam 3: BFE suggest that a G36 and AT4 were usable at one point.
T.E.O.R was scrapped because investors and publishers decided to pull the plug on it. Since Croteam was doing it on a “work-for-hire” basis, they resumed work on other projects after this game was canceled. However, it served as an excellent example as to what Serious Engine 3 was capable of, several years before Serious Sam 3 came out.
The AK-47's magazine model and weapon texture appear in the Serious Sam HD game files but have no connections to anything in the actual game. They are most likely leftovers from T.E.O.R.
A model named “gunner_01.mdl” in Serious Sam 3's files has animations named “idle_scar”, “idle_at4” and “idle_g36”. These appear to be leftovers from T.E.O.R, as a screenshot of it featured a SCAR-H.
- The M29 Infantry Assault Rifle's animations have “AK47” in its name. It's possible that the M29's animations were originally based off of the AK-47's, but were changed during production to be more fitting for the M29.