premise: Team Fortress 2 was incapable of being developed.
hypothesis: Team Fortress 2 ( TF2 ) is a team-based multiplayer first-person shooter video game developed and published by Valve Corporation . The development is led by John Cook and Robin Walker , creators of the original Team Fortress . Announced in 1998 , the game once had more realistic , militaristic visuals and gameplay , but this changed over the protracted nine-year development .