Challenging and addictive.
To start off I was already impressed with the unique introduction. The tutorial was lengthy and useful also. Different game types are always good but you can never have too many. The variety of characters to choose from was handy and the idea itself is a creative one. I thought the sounds suited the style of the game, and the added effects, particularily when the countdown to the fight was made, was pretty good.
It looks like a lot of effort was put into making this flash and I hope its paid off. All I would've liked would for the fighting to be a bit more detailed, the one button was a little dull. Still, the weapons was a good idea, could always have more to choose from there aswell. Another thing is some of the levels were very easy due to the gaps in the middle. If you stood in a certain position after knocking down an enemy first, he'd drop and continue to fall down the same hole until the level ended. Apart from that this game is definatly worth playing, nice idea of the high scores too, not that I was good enough to get on them.
I look forward to more from you, good job.