Very Cool!
Unique take on the "avoiding past selves", since you do have some control as to when they spawn and despawn. Other games have it constant which make the whole level chaos, but this has moments of downtime and thinking, which I enjoyed.
I found the controls a bit uncomfortable, since I am used to WASD + Space. Would be nice to have some other movement options, especially when I need to be able to be precise with my movement.
I think level 9 was the most showing of the mechanic, of how quickly things can get out of control, as well as needing to use your past selves to get the height. Also found out that you can just keep rising if you don't move after picking up a gem, would be cool to see that in a level :)
It was really fun to watch a completed level play over, to see the barely working contraption that you've made, watching over your narrow escapes and such was cool.
Level 11 was probably my favorite, since you were able to just ride on top of the green past the whole way through lol.
A mechanic I think that could've been used more was killing out past recordings, since I found it interesting that lets say if you recorded a green, then used that green for your blue recording, and then killed the green recording, it would still keep the blue, even though they would be standing on nothing.
Visuals and theme were nice, would definitely benefit from some music.
Nice job!