It uses RandomSpawner, which is a class that isn't yet implemented in Vavoom, maybe there are some other unsupported things there, but that's the main one I can see .
I've been playing around to implement that RandomSpawner class, it seems to be working fine, I'll send it to Janis so he can tell if it can be added to Vavoom for the next version, the rest of the problems it has seem to be related to small syntax errors, it's not too difficult to make it work .