Thanks for the feedback. Versus mode lets you select a stage a play, choosing from the bonus stages as well as the arcade levels - both modes allow up to four players, human or computer.
The paint % idea is interesting and I'll implement that in the final game, I also want to come up with some other fun bonus stages that put all the players on an even playing field. If I do create further modes mixing up the stage layout, it'll be after the arcade and versus modes are finished and polished up (adding items and modifiers, cutscenes, etc).