Not bad, there is a potential in it. Although it gets rough quite fast. I would change one thing though: the button for jumping should be "w", not "space". Besides inconvenience of using the space bar: if you play the game without full screen turned on pressing space moves the screen down.
PS
The upgrades should drop to the ground, because if you kill a bat too high there is no way to pick the upgrade. Oh, maybe you could add something like a prestige system? With permanent bonuses?