An okay game, but it's not very refined. It isn't clear what most of the upgrades do, and preventing damage to your crates seems very difficult considering the enemy has ranged weapons and there's no cover.
The 'revival' mechanic when you die is broken, as well. The enemy still targets your corpse, which means if you are mobbed, it's essentially game over. You wait for revival, survive for an instant before the same 20 guys who originally killed you kill you again.
Nice effort, I guess.