Cool game! I got very engaged and wanted to get the 5 upgrades (which I did achieve), and the game has an interesting concept, and has ways to improve it to make it even more original. And thanks a lot for controller support, +1 star in gameplay. It lacked a story and graphics, and I would suggest a menu or something to tell the player how many upgrades he has, maybe an end too? Also tell the player in someway that they damaged the enemy. It could be by flashing the enemy or a sound.
P.S. The fly bug mentionned by Psy is real, got to do it too. Also noticed a bug using this; in the kind of pipe under the purple upgrade, you can use this bug to gain speed and go through the floor, making the process to get the purple upgrade faster.