This is one cool game. It is a side scrolling beat em up type game like Final Fight, however this one offers much more in terms of gameplay and graphics. First of all, the game is done in polygon style, with graphics that looks similar to Tekken 2 and Shadow Struggle. (It's made by Banpresto, the same company that did Shadow Struggle). As you go through the levels you are basically on 2 plains (can't move up or down, pressing up jumps, like a fighting game), but you can jump back and forth to the far plain by pressing L2 or R2. You have special moves like a fighting game, and some of them are really cool (laser sword, multi kick attacks, etc.).
You go through the levels fighting minor enemies with small powerbars, until you reach the end of that zone and fight a boss with a lot more power. You have one life, but you have multiple life bars like in Killer Instinct or Dragon Ball Z Ultimate Battle 22. As you fight your way past enemies, you can gain more health, and you also get more health by passing a level. I've gotten over 2000 hit points at one time, and had more than 10 life bars. The better you do, the more life you gain, so taking less pain in the first few levels means you'll have a lot more life when you reach the higher ones.
I'd say this is the coolest side scroller on psx as of now, and one of the coolest side scrollers I've ever played, period. It's an import game, but if you're lucky enough to get a hold of it, don't pass up the chance.
Here is a code you get after beating the game: at the title screen, hold left for 3 seconds, then press right, O, Triangle. This will add an extra difficulty in the options called "extra" that lets you always play in hyper mode (you flash and can do moves really fast with no lag time, like the super cherry in Tobal Quest mode, and you can keep hitting the enemy nonstop for super cool combos). The downside to this code is it gives the enemies hyper power too, so they whoop on you better. Hit them first, or you'll take major pain.