This game really has charm! Especially with the music it reminded me of old school arcade games. I felt like the graphics had a certain appeal that fit the game nicely, though the main character could have deserved a bit more attention. It felt really fun rolling around as just a head, but it would have maybe been cool if there were multiple stages of self destruction, which each had their own unique properties!
I do agree with the other commenter that the jump felt a little bit floaty, and during the boss fight sometimes the robots were spawned so close together that I couldn't jump between/over them. I also really like the idea of intentionally taking damage to explore otherwise inaccessible areas, but of course it would be nice to reward the player somehow for taking that risk.