Hey, thanks for playing!
The mechanic of hooking onto a floor (or ceiling) is semi-intentional. I wasn't originally planning on it being a thing but one I discovered it myself I thought I'd try it. That one jump in level 3 Qwott got stuck on basically requires it. That or damage boosting. Bit of a troll that one. I'll probably keep it in but remove any parts of the game that require it to progress.
Level selection will be a thing. But as you discovered you can reset the game by deleting the save file for now.
As for the indicator, do you mean have it appear the moment the player launches the hook? I suppose that could help. I do plan to make things more lenient if you miss though. Right now the only way to reset your hook is to fall to the ground or jump off the hook. I'll eventually make it so you can also re-hook if you get hit or after a failed attempt once the hook has fully returned. Not being able to do that and just waiting to hit the ground is frustrating I found myself.