a Nef-rune that improves weapon knockback... what an awesome diablo 2 reference. overall gameplay was very great, but far too short! 5/5. just the armorgames link annoyed me when i fought in the top left corner.
the worst energy system i have seen so far: i can do 2 battles including healing, then i have to wait for 2 hours. what is the point of a game that can't be played?
4/5. Nice game, but not too fancy or innovative. FOR HARD MODE: It is enough to upgrade the pistols' damage, then save up $10.000 for M16. Upgrade its' damage, too (and only its' damage). Then go for the Gatling. Upgrade it completely and you've got what it needs to beat the game. Everything else is just dodging by jumping.
Your game has potential. It is a well-rounded launch game. Unfortunately I find the "strength" to be rather negative, as it is easy to dodge objects on your way up, but one can use the slow-effect when falling, if being LOW on strength. Maybe you can make that attribute mono-directional?