The movement of the car seems a bit off in my opinion and having every collosion result in an game over while the space between obstacles is narrow seem´s unfair, BUT considering this game is meant for short rounds that´s totally fine with me. Otherwise good choice in music and nice concept :D
i see a lot of potential ( and the work :-P)
like already mentioned, I miss a return button, some more levels, maybe even different levels depending on the outgoing of the battle. The aim need´s work and while clicking on the build button I always command the tank standing behind the menu.