For anyone who wants to make a Geometry Dash style game, here’s a good example- it’s not done, but still you’ll get the idea. It says “example” but it’s still a game 
There’s a bug where you die spontaneously every once in a while, that’s because of the horrible collision system that I’ll fix later 
Feel free to copy any of the logic if you want.
Currently there’s the basic square logic, X2 speed and a UFO system; plus the obstacles. I did the UFO first 'cuz it’s probably the easiest to make, I’ll do the rest afterward.
Play it here: http://flowlab.io/game/play/677003
I know you said you’d fix it later…
But it seems like a change to a circle hitbox on your square and changing the jump impulse to 14 does the trick 
Huh. I’ll try that out… when I get my laptop, thanks for the solution!