The phrase "debut game" refers to the first or initial video game created by a person or a development studio. It is like the first time they are entering the gaming world with their own creation. Full definition
Sorry the Ox, 9 goals in successive games and 5 goals in debut games isn't that welcoming! (justarsenal.com)
Titanfall, the all new debut game from developer Respawn Entertainment, got its release date today. (techraptor.net)
Michigan senior QB Jake Rudock didn't have the prettiest debut game for the Wolverines Thursday against Utah, throwing for two touchdowns and three interceptions. (diehardsport.com)