A spin-off game of the same title was announced during the last episode of KonoSuba! 2(この素晴らしい世界に祝福を!2)that aired yesterday (15th March). According to the announcement, the game will be made by 5pb.. The platforms and genre are yet to be unveiled.
KonoSuba! revolves around Kazuma Sato, a dead teenager who gets resurrected in a reality that imitates the world in RPG.
Official website: http://5pb.jp/games/konosuba/