Would be pretty cool for something like a timer when running through to see how far you have gone ahead in the level or something to judge progress.
Might be a bit picky but the rolling animation seemed a bit off to me and there were also times I couldn't fit through some holes, which makes it feel that there isn't any different paths and only one select path through the entire game. 

Pretty fun game, would've been nice to have a score at the top to check my progress