Not really a cheat but... On the Hospital Level, stay at the big balcony, not the small. There's a slim chance for this to happen. If someone "invisible" comes up watch and see them go over the balcony. They might float in midar and shoot at you. But the floating really bugs me...
-HOW TO OBTAIN THE AWESOMEST AND COOLIEST SCOURGE SPLIITTER!-
Beat "Time to Split" with a gold or silver ranking. -How to obtain "Streets" arcade level and the "Cardboard" cheat- Beat Space Station
-How to obtain bosses of each level-
Almost true with every level... Beat it on normal(first level gives you mutant)
On the challenges menu select behead the undead and then select fight off the living dead. you have a shotgun and to behead with it you get 75 points if you use your fists with a good smack you can behead and score 100 points.