This game is great but it suffers from a game-breaking problem if you got it for on-line coop. When the host quits or all characters are defeated everyone except the host gets reset to no skills. They still get all the money to buy the upgrades, but the stores are often hidden or locked behind doors, so it's often only possible to get all your skills back if you're close to finishing a stage.

This effectively kills the game for on-line coop. Here's to hoping it gets fixed soon.