An awesome game right up until the final boss with whom I have some complaints.
The game is a lot of fun with a simple control scheme utilizing 3 buttons. It latches unto two mechanics (speed maintenance and slashing) and everything in the game centers around those two.
The one issue that I have is that the final boss is rather underwhelming. It is not really that hard, but it has a gigantic healthpool making it more of a test of endurance than a test of skill, and consequently managing to bore me as I defeated it. It also throws the speed maintenance aspect out of the game completely, letting dashing down at the bottom of the screen an unpunished act, something that would otherwise only be the case when using the potion.
But asides from the boss, I'd say that the game really is a lot of fun and once you get past it, the fun keeps going in survival mode.