Excellent, but room to improve
Excellent game guys. It strikes very much of Super Smash Bros.
The one major thing I felt missing is when different 'players' have the same character, i.e. you play as P-bot, and your opponent plays as P-bot, on screen they look exactly the same.
Surely adding an aura or even a border with different colors would be relatively painless (you already do it for the power ups). Even just an arrow above the head would help or possibly add a key that when pressed 'identifies' your character, i.e. pressing 'f' will make your character glow, or put an arrow above it.
This is mainly annoying playing as Convict. Maybe his shape-shifted form should be darker (or brighter), anything to differentiate it from the 'real' one.