I love this little puzzle game! The mechanic is quite unique and I really appreciate anything that as not done much before! The puzzles themselves are good, and the art is fitting too! Tripping the enemies is such a nice touch that it's something that only a rope can do in this case. Good job!
For things to improve I'd say please put the controls in the game. Your first two levels is already a perfect place for some text/image to be placed, and would make the player's experience much better. I would also point out that tying and untying action lacks an animation, and that pause sometimes make me wonder if my inputs was lost for some reason. It would be good if there is some visual effects that notify the player something is acted upon.
Anyway, this is a very nice puzzle game and I like it a lot. Keep up the good work!