The Infinity Combat Prototype is a standalone game released in May of 2006 (revised January 2007), created specifically to tests the graphics, physics, and networking engine, as well as test flight controls, mechanics, and combat for the future game. The Combat Prototype does not allow the player to perform any other game functions besides combat (i.e., planetary landings, trading, exploration, etc.), and shares only the game engine with the base game (as such, it should not be taken to represent the final game). As opposed to Infinity's open-ended sandbox gameplay, the Combat Prototype is arena (team vs. team) based. The player is only allowed to pick from 10 different models of starships.