This seems like a neat idea! ^_^
Some of the movement could use a bit of polish--but then, this is a jam game, after all!
I do second the commenter who noted that it's possible to grapple beneath the level; I actually made a fair bit of progress in that way on level three (I think that it was). Alas, I then fell--and encountered no "kill collider", leaving me stuck pacing an endless void... o_o
Finally, I wonder whether the levels might not benefit from a bit more space in which to work, extending the time that the player spends and the distance that they can cover in a single grapple. However, that's highly speculative--it may improve the game, and it may not!
All that said, I had fun playing this! ^_^