Great game! There are no levels yet, but I'm really looking forward to it! Also it's really polished.
Some things to improve: First, add WASD controls; that shouldn't be too hard. Also, if you hit a wall while rotating, multiple bounce sounds will be played at once. Maybe make a variable that is to false by default and if you touch a wall, it gets set to true. If you don't touch the wall, set it back to false. If it's true, you can't play bounce sounds. That's a solution I just came up with, idk.
Also, movement is a bit jittery. I had this in unity because I used a lot of loops in my main script, but you are using gm, so the reason can be different.
Although there isn't much gameplay yet, it's satisfying to play and I'm looking forward to see what that other dude does :D