I completely agree with the praise from other comments, I will not repeat it here.
I have one big annoyance - why o why do you not have something like "r to restart" in the tutorial? It allows you to lock yourself quite easily, and no indication that you did something wrong.
And one small annoyance, in the later levels, when you understand the mechanics, when I got an idea how to do it, I needed to kill myself repeatedly to try it. In most of the levels it was clear where to commit the suicide, so I needed to travel there (repeatedly) and it adds nothing to the gameplay. (In one of the levels that was actually a game mechanic (you need to keep access to something to kill yourself), which was nice. )

