That was such a complete game! I loved the level design of going around in the world and wrapping back to the start to get more abilities to progress further on. The main boss that kept coming back during throughout parts of the game was a really good theme as well. The squash and stretch animations were solid and the controls were super snappy. Also, that music deserves 5 stars, it was amazing and triumphant as you traversed the levels!
A few nitpicks: the costume changing can feel a bit cumbersome at times once you get so many that you have to cycle through them all to get to the right one but that can also be part of the challenge of collecting them all and sometimes the UI on the top left would cover the player or some important parts of the levels/pickups.
Other than that I loved this entry, very solid game jam game!