Way too easy to get stuck on shit. Landed on top of a blimp and stayed there for a good five minutes, then had an airplane run into me, which caused us both to just hover in place until I ran out of fuel.
I love how people call this a rip off of Upgrade Complete. God forbid anyone makes a top down shooter that involves upgrades. You people are god damn idiots.
@Okayasia, Deathwing11: Same thing happened to me on 5-1. Maybe it happens if you save and exit. SUcks that I got all the way to the end and can't do the last level.