In vision-based interfaces for video games, gestures are used as commands for the games instead of pressing buttons on a keyboard or moving a mouse. In these interfaces, unintentional movements and continuous gestures must be supported to provide the user with a more natural interface. This paper proposes a novel gesture spotting method that combines gesture spotting with gesture recognition. It recognizes the meaningful movements while concurrently separating unintentional movements from a given image sequence. We applied our method to the recognition of upper-body gestures as the interface between a video game (Quake II) and its user. Experimental results show that the proposed method is, on average, 93.36% reliable in spotting gestures from continuous gestures, confirming its potential for a gesture-based interface for computer games.