A fun game! The music, sprites, and sound effects blend very well with each other! The game is simple but well-made. The control works exactly as you would expect. The sprites are very good!
To make the game better, it is probably good to have more space at the border or to keep the character at the center of the camera. Not in full screen, the game doesn't feel great, and with full screen, it is still difficult to have good control over the character when it is close to the edge. Also, the death mechanic feels a bit weird. Other than the ghost form which trivializes the entire game, the other form seems to just be a more difficult version of the first as you start deeper. And I doubt that many people can reach the boss without ghost form. So it is probably a good idea to adjust the respawn mechanic to provide more perks.
Overall, this is a fun game with beautiful music and sprite. I especially like the mspaint intro, it is energetic and full of character. Good job!