I use art money for the gold. You cannot go above 900k and join a co op or the game will hang. So for now the safe limit is 400k gold. It is a bit like metal slug and needs tweaking for the hang/slide and slam moves.
Argh! How do you beat that annoying Overlord?! Everytime I try he manages to outrun me, since I need to constantly deal with silly jumps. And after he outruns me I can't see my character any longer and thus can't progress.
You want to be wearing stuff with +Speed and +Jump on it like the Athletic Socks, or the Stunt gear. I used the EVA backpack because it lowers gravity gives jump and when you use hangtime you can fly pretty fast with it.