Very simple game with decent art. Lots of bugs (Chrome): upgrading the defense changes the earnings icon while upgrading earnings doesn't, all of the icons during the shop screen are 'lit' until you press one to change screens, the music randomly mutes when using space to fire, and the guns... After you buy the rifle, firing the shotgun causes it to change back to the pistol, making it impossible to use the shotgun (after pausing and unpausing with the shotgun equipped, the problem went away), and the final weapon would only fire once and then never reload. Could be because I bought the last weapon first. Also, why am I able to buy the same weapon more than once?
Not bad for your first game, but it's not great.