Good idea. However, the controls are confusing (speed changes randomly, although I think it is because of "being on ice"), the grappling hook has too long cooldown.
Viewing post in IceCubed jam comments
I am thinking you could collect a new grappling hook as a "power-up" or an item every few platforms. People would have to jump up to it to get it and use it as they please, but only once, so it adds a depth in deciding if this is the good time to use it. Then there would be checkpoints in case they fell down, so they can respawn and use that grappling hook again.