i found kinda a cheat for the timed modes ^^ when theres like 2 enemies, dont kill them and other monsters wont spawn so u can just keep dodging two of them until time runs out instead of facing heaps.
guys i have a reaaally good way to get money. what u do, get the dumpster and rocket#4 then go up really high, do two backflips while superman'ing and throw in a up-n-out flip then dumpster dive OR just land and keep tapping the keys for handstand wheelie. :)