I absolutely liked that, really cool challenge!
Well... here are my sugestions for next update (or maybe for 2.0):
- Add a Timer for the char to live... if it goes 0sec you lost it... to have more lifetime... collect coins, stars, 1-UPs (any kind of collectable you want) so your char can last longer, but you also have a max lifetime limit for the char like... you can't farm coins to gain more time on your clock and go past 10 mins
- Add Ironman mode, which is like, picking ONLY one char, and you can't switch. if you die, then your run ends, you're eliminated (or maybe something like that... well i'll leave that up to you)