The concept is quite simple yet very interesting and in my opinion has great potential (and adheres to the theme well) . I like that you are forced to use the swinging mechanic if you want to maneuver to the upper half of the screen, since the rope cannot be shortened up to that point. However, the current state of the game is way too difficult (not surprised given the title), and can be downright impossible in certain combinations of randomly generated enemies.
But I do think this has the potential to be a really fun game if the enemy spawns are not purely random and somehow designed to take advantage of the mechanic. For instance putting some enemies that requires swinging in order to "break" through them, or perhaps some powerups that are on the upper half of the screen and will require you to risk swinging to get.
While I like the aesthetics, it may also be cool if some context is added to it in the future. For example instead of just abstract objects you could be some captive person dodging bullets or something.
As for UI, it would be nice to have some visual indication that the "rope" cannot be shortened beyond the halfway point. I was a bit confused at first why I couldn't move up past the middle.