Nice polish! From the main menu with the title dropping down to all the bits of SFX, visual queues.
I appreciate the challenges of designing the game to have an invisible tutorial - I'd say you succeeded. It was quite clear what I was supposed to do as a player. One suggestion I would make is have the mouse turn into scissors while in the game window? Or maybe even just when it's over strings?
Question Why wouldn't you trade stars for extra scissors? Is there any other way to spend your stars?
The stars are a nice touch - as a bonus, not necessary to complete the level, but to encourage the player to give it extra thought.
Excellent work!