It's a pretty good concept but definitely falls apart on the execution. The physics feels really buggy and the player is way too large and sluggish so moving around is annoying, combined with the lose effect hurting my eyes makes it extremely tough, and not in a good way.
I also didn't really understand what platforms were an instant loss and what platforms you can destroy with no issues. I think clearing that up would help the gameplay a lot.
Overall it's quite rough, but I can see it being a fun-but-hard platformer with a bit of work.