A couple of easy hints I have seen in this game that should help anyone having a hard time with this:
Straight lines that are against the edge of the tilemap should go parallel (Same direction) as the edge it's going along. Same thing goes with 3-way joints, just simply turn those facing towards the inside of the tilemap.
Another hint would be to make sure that the 4-way joints are always connected to something. Hence this game.
Preferably, I like starting from one point and going on from there in a chain. I find it easier that way.
As for this game, really nice idea, but it becomes a little frustrating after a while, especially since you have to go through 50 of those puzzles just to get an achievement. However, the way they're jumbled together really makes it kind of fresh and new each time.
Now this is is what I call a puzzle game! You get the user to think intuitively and give him a reason to remember things in order to get past the puzzles. It also requires past knowledge of certain things like music and such! That, mixed with the compelling and magnetizing storyline make this an incredible game!
That, with an easy user interface and simple game play also make this one top notch game. There are so many things I could say about it, but there's not enough time, so the most I will leave you with is a favorite and a perfect score if I were one of those fancy game critic guys.
You, kind sir, rock all kinds of hard!