Nice work! I hope you don't mind if I give some feedback:

• It's usually not a good idea to let the player buttonmash. You can use a variable and see how long ago it was since the player shot, and if that time is above a threshold then you can let the player shoot. Or you can just let the player hold down for some rapid fire.
• Great work with adding animations and sound, just getting them in their is really neat!
• Movement is kind of stiff, I think GMTK has a video on celestes movement, check that out for some inspiration

All in all, awesome work!