It's funny how ten minutes ago, I've written a comment on a different platformer in this jam, where I said that it would be cool if the UI elements could be used as platforms. I guess you get what you ask for after all :)
I'm gonna start with an obvious problem in this game. Manipulating the volume would be so much more powerful, if there was any sound in the game. I mean, music always builds atmosphere and all, but in your game you literally use the volume slider! That is an awesome mechanic, that you undercut by not having audio. If you want some free music why not check mobygratis.com, they have hundreds of tracks, by Moby, that you can use for free for noncommercial projects. Just a hint :)
The graphic style is simple, but very readable. No complaints on that part :)
The main mechanic really cool, and I can only imagine what you could do with it with more time (opening the pause menu, as a source of new platforms for example).
Also- I liked the difficulty progression. The last level gave me a pause, but then I got, that I need to use all the mechanics I already know. And that felt satisfying!
Over all- really run puzzle platformer, with a great twist, that maybe needs a bit of polish. Keep it up man!