This puzzle concept is completely mind-boggling in the good way!
The instructions feel completely unintuitive, though. I didn't get that I needed a "closed" loop, and each loop mustn't cross with each other or include other figures in it.
I had to learn those rules by brute force, which isn't helped by the fact that the lines are hard as heck to distinguish from the background.
Also, I had to complete the game thrice to understand that the game didn't get stuck, just that I had finished the 7 levels. A clearer indicator that the game's ended or a level counter would be much welcome.