The game plays as a 2D brawler, similarly to the Shinobi games or Ninja Gaiden. The levels require tactics and precision, with almost no room for error, as you only have one hit point. However, you have infinite rewinds, which is cleverly explained as the main character Zero playing out the combat in his mind. When you succeed in passing an area, you see a replay, but contextualized as Zero actually performing what he has simulated in his mind. The game calls it precognition, and it is central to the story. Pretty clever.