There's not a lot to say which hasn't been said in reviews already. The Gamespot review in particular hit the nail on the head if you ask me.
It's a side scrolling brawler/platformer with one fundamental flaw: you can't cancel attack animations, and unfortunately said animations are elaborate and long. This means you will get hit a lot without any chance to defend yourself. It may look like an exciting action game based on reactions and skill, but it's really more about memorization of enemy placement. Rayne has a couple of attacks that send your opponents flying into the corner of the screen. If you send an enemy flying he will catch every enemy between him and the corner as well. What you want to do is pile up enemies in a corner and finish them all at the same so no-one can sneak up behind you. That's really all there is to it in a nutshell. Well, that and the occasional platforming hell sections. The lengthy animations you can't cancel out of give the whole thing a very sluggish feel and the game als loves to knock you down the very moment you manage to get up. Basically the game is hard for all the wrong reasons.
It's an old school game, but as Jim Sterling wisely said on numerous occasions: 95% of these old games are shit, and people need to accept that. He gave BlooRayne a 2/10 by the way. (I don't agree with that score, because I did have some fun with it. The written review is pretty spot-on, though)