Originally released for the Sega Dreamcast and arcade, Power Stone and Power Stone 2 are bundled neatly into the Power Stone Collection for PlayStation Portable. Both games involve 3D fighting, consisting mainly of punches and kicks, but players can also collect power stones to turn their characters into super fighters who cause more damage than their counterpart. Power Stone features an "Arcade" mode for single players that includes unlimited continues and such bonuses as weapons, characters, galleries, additional modes, and more. "Versus" mode allows up to two competitors to duke it out with one of 15 available characters.

Power Stone 2 features a variety of single-player options and multiplayer action with the inclusion four-player combat in multi-tiered levels. Modes of play include a single-player "Adventure" that allows solo gamers to fight enemies for items and gold to use in other areas of the game. "Basic" is another single-player game that includes unlimited continues and matches that lead to a final boss battle. The final single-player option is "Arcade," which pits gamers against three competitors at a time. "Original" mode allows up to four friends to duke it out in one-on-three, two-vs-two, or tag team tussles by using a wireless connection. The game also includes a mini-game in which players must defeat their opponents while the level is blasted with falling bombs. Both games feature a training arena and "Screenshot" mode.