Good game!
This game is fun to play and it's obvious you've put some time and effort into it. Here are some thing I picked up on whilst playing it:
-Why do you have to go through the tutorial each time you go back to the main menu?
-The level up menu should be on the same screen as the customisation menu, that's a must, it's annoying how you can only view your level up stats when in battle.
-How come you get the same experience points on every single fight? Surely you would get more xp on later levels, also you should make the xp reward depend on how little damage you or how much damage you inflict on enemies.
-I don't know if this is on purpose or not but when you activate the barrier in a fight with a machine gun enemy, when he shoots you, you actually gain health and the health bar goes off the screen.
-The damage system seems very flawed...all you have to do is put about 6 points on defence and then activate barrier in a fight and you can't lose.
-I completed the game and even did some bonus levels and I still have not unlocked the TANKDIETY medal...
-The fighting animations seem pretty jumpy
-I really don't the choice of music you've chosen for the game, I reckon you should consider changing it. I kind of confuses things, I mean you got some Castle Crasher music as the main theme when it's a Tankmen game and you've also got som Madness music which confuses things even more.
So yeah, cool game but I reckon you should make an update soon.