The game is actually very good. It's pretty different, but the hand-to-hand combat is quite fun and the story and presentation are EXCELLENT. Definatly pick it up at this price if you can, after knowing how good it is I'd have easilly payed $30 or $40 for it. Unfortunalty it sold quite horribly, which may explain the quick price drop. Hopefully it'll get a bit more recognition now, it's one of the most underrated games of the year (I can't understand why it got such mediocre reviews, it has it's flaws but it's still much better than most any other game released recently...save for Ninja Gaiden).
And Renzo, did you use that shockwave attack much? Works great against multiple enemies, pretty much damages and knocks out every enemy in front of you. Then once they're all knocked down go up to one and beat the crap out of him while he's getting up. Also attacking one enemy and then quickly switching targets and attacking another works much better than trying to attack just one target when up against multiple enemies.