I really like this... a few things
I really like this. Solid Game.
A few thoughts/ideas on what would make it better.
1) Purchasing of missiles (?)
2) Reset missiles seems odd that after you die, you have the same number of missiles left when you restart. One's better off reloading after one dies.
3) Purchase repairs?--Continual damage among the levels?
4) Smoke screens etc... could be cool.
5) Enemy tanks
7) Additional power-ups, of various kinds.
8) Is there a purpose to the different "sights"? If there is, I don't see it. Worthily of clarifying.
9) Increase damange on shots?
10) Different terrain?
11) An "adventure mode"
Bottom line: This game has some serious potential. Hopefully, it won't fall under "cancelled" projects for you.