I only like the first one actually. The other 3 look a bit too much like a (not so well) attempt to go retro.
Edit: I’m not that into the dubstep scene, so my opinion may very well be invalid.
Edit2: are the low resolution background images on purpose? I think they’re the reason I don’t like the last 3.
its not that the resolution was low, its that i blew up the brushes bigger than i should have. but these are going to be on a tiny ipod screen or thumbnail sized icon, so its not really a problem