i have a few suggestions, 1-i think yu should add enemies that if get damaged, say arghh or something if i made it to shout it, 2-yu should do walking NPCs plez its cool if its walking in a somewhat way. 3-add stages to 1 level? if yknow what i mean :)
instead of 2-4 heli that gives crate or idk..... it should give a minigun and a dart monkey holding it, with umm... and the appearance should be a tri carrieer