Pretty neat little game! I liked the feeling of starting out as a broken-down and slow robot and gradually becoming more powerful. Personally I wasn't bothered by the slow pace that much, but perhaps giving the running upgrade earlier on could alleviate the slowness concerns that others had?
The sprite and animation for the player looked great, especially the whip attack, and the art style in general was very nice, although some rooms felt a bit big and empty. The camera sometimes seemed to go out of sync with the player and swing around weirdly. There might not have been that many opportunities to die, but the falling pipe effect when dying was really funny!
The enemies and bosses were simple but effective, though the basic floating drone enemy was a bit too fast and punishing in my opinion. The boss bee was a kind of a one-dimensional fight - much like the regular variant, its attacks were too fast to really punish them, so I found the easiest way to deal with it was to wait for it to float to the bottom level and hit it from behind. On the other hand, the monkey boss had a nice little buildup where he showed up before the actual fight, although the fight itself was very easy (his leaping attack seemed to miss most of the time).
All in all, the game could use a bit of polish here and there, but the story and idea definitely has a lot of potential. Good job!