Grinning Cobossus is an online 2D Flash vertical Shoot'Em Up game developed by Gama11. Grinning Cobossus is a game that basically only consists of one level - which is a fight against the titular foe. However, this game features 3 difficulty settings (Easy, Medium, and Hard), survival mode, and up to 12 achievements earnable over the course of play. Will you be able to kill the cobossus? This game can be played at here.