Oh No! is a fast paced shoot'em up with multi directional scrolling. Taking place in the far far future, you'll take the role of a ox breeder. Using your ship Badjak, your objective is to prevent aliens from taking away your oxes. To your disposal you have two kinds of weapons, a laser and a boomerang weapon shot from the rear. You can get a new ox if you destroy one of the ox parents occasionally appearing on the play field. There's eight worlds in the game. To complete a world you need to defeat nine alien waves. The game is lost when all oxes have been taken away.