So the best solution is to create a different gamestate for Custom levels, which does not display the usual title and completion screen, and also doesn't allow the player to collect money.
Since Blocky Man is nearing completion, I'll probably get my next game project started while I'm finishing Blocky Man. The concept is basically to do a side scrolling beat-em-up like streets of rage. The current title is "Fists of Justice", and yes it's supposed to corny[grin]
Then again, if I like the elements in 4E6, I might enter that instead.