Collision detection/enemy death animations don't always seem to work as before I got mission completion my shots were going clear through some aliens while shooting in an entirely different direction some were still dying.

I'd also suggest improving the rotation speed of the tank hull itself as that felt needlessly sluggish, especially if you do improve the game to provide incentive to actually move the tank.

Decent

good it is hard and challenging this is fun and awesome

"Same Mission; over and over."

It's pretty boring, to be flat-out. There doesn't seem to be much reason to move around with the tank, since the cannon is able to shoot so fast - it makes more sense to just sit in the middle of the level and pop enemies off rapidly as they come in. The missions felt the same throughout the levels, which I understand is meant to be the case, but it should have some more variety.

The lack of a pause button is a bit annoying with games like these, since you want to be able to hop off for a few, or end the repetition and cling to sanity. All in all, not too good - but not too bad.

No replay value,
VKL.