Very cool idea. I think the character controller is a bit unwieldy, with too little acceleration and inconsistent jump heights. Tightening them up would definitely help showcase your ideas much better, I feel. Also, more feedback on what the gravity ability is doing would be nice, it seems very disorienting to use. Maybe an arrow to show which direction gravity is going when its not straight down, or changing the rotation of the camera. Something minor to help keep player's grounded, yknow?
Design wise, I'm curious as to what the game would be like if there was more of a drawback to having more abilities, and being able to "abandon" certain abilities. Maybe the ball gains more mass when it has more abilities, and can't jump as high or dash as far, so you have to let go of your gravity manipulation to get somewhere or something. There's a lot more to explore, imo. Good work :).