The levels of rewards you get from each task are based on your performance so the better you do the faster you level. (fifasoccerblog.com)
All characters and arenas are unlocked from the get, so the only reward you get for progressing is unlocking new arms for your fighters. (thezombiechimp.com)
The sense of reward you get is better than any game anywhere on any platform. (nintendotoday.com)