a cute little game with a nice aesthetic! reminds me of the "Learn to Fly" flash game everyone played years ago.
being "joined together" to something you need to NOT shoot is a cool take on the theme!
aesthetically, for pixel art, try making all of the pixels in the game the same size (i.e., making every asset the same resolution). this helps make the game feel more cohesive, instead of some elements being hi-res and others being really blocky
the cannon feels kinda tough to aim (maybe a guiding line could help?), and the cooldown can also make it feel unresponsive (since you can't tell when it's on cooldown).
also it's kinda tedious to slowly float upward every time you restart
overall i enjoyed it!