The combat is designed/executed better than some older big-console fighting games. Everything is smoothly animated and feels like you're cracking bones. Each character has a well-imagined set of moves. One very large problem, however. Glitch lagging. Characters get stuck spinning in circles or below perspective horizon if they stress collision detection. This only happens on off occasion, however. Thrilling ass-kicking is more normal.
The roster of characters is well-chosen, but never assume a character can't fit simply because he/she/it did not come from an action-based video.
A Nyan Caxx with 450% speed, next-to-no HP, and attacks including rainbow-barf projectiles and a limited-circumstance darkness form (which by contrast would have high HP and damage & be slower) could be ludicrous, but still extremely awesome. [Don't take that seriously.]