One the Dreamcast's best fighters, and that's saying a lot.
Power Stone is a 3D fighter that has your basic arcade mode and a VS mode. In arcade mode, you go through some fights around the world, searching for the power stone, until you reach the boss. In VS mode, you can play 2 player. There are a lot of options you can adjust, which is nice.
The basic gameplay involves players trying to eliminate the other players 5 vertical health bars. This health system is really cool, and can provide some intense multiplayer action. You can do punches, kicks, jumping attacks, reverses, combos, and all that stuff. There are 3 "stones" around the level. If you collect all 3, you can do special attacks to destroy a large chunk of health. The really cool thing about the fighting is the interaction with the environment. You can pick up chairs and throw it at people. If your big, you can pick up a pole and swing it at someone. If your small you can spin around on the same pole to attempt a kicking attack. In some levels, you can climb on the ceiling. There is also weapons scattered around levels. So you'll be finding players fighting over, swords, pistols, rocket launchers, bombs, flame throwers, and more good stuff.
The fighting is very deep and separates itself from other fighters. At the same time, Power Stone is easy to pick up and play. It's a fantastic multiplayer experience, also.
The graphics in Power Stone are good. The levels are nice and varied. The environments look very nice, and the character models are good enough. The animation is smooth. The framerate does dip a little when lots of action is going on. Power Stone doesn't look as good as, say Soul Calibur or Dead or Alive 2. But that is to be expected due to the games art style.
The music is OK. It is nice and varied for each level. The voices are very Japanese. There is nothing truly special about the audio. Everything is passable and doesn't take away the experience.
Power is fairly expensive for its age. You should find a good deal though. You get your money's worth if you're interested. Power Stone is loaded with extras. VMU minigames are included. There's a ton of stuff to unlock for beating single player. 2 player should keep you busy for a long time.
Power Stone is classic. It's one of my favorite fighters of all time, 2D or 3D. The question you're probably asking is, "Should I get Power Stone Collection for the PSP?" The answer is only if you like Power Stone 2. I wouldn't though, if I were you. You can usually find this pretty cheap. Either way, get your hands on this game!