Not a difficult puzzle, but the graphics are clean and the play is solid. In the first few levels you get the hang of the game, and it doesn't really change much, so it's just a matter of clicking all the pieces until they fall into place. Not much challenge, but a fun game to click through. Watching the path shapes take form is oddly satisfying.
Suggestions:
I'd suggest music, but I'm OK to add my own soundtrack. Some trippy acid-rock stuff seems to work well.
Would be cool if the stars would slowly phase from one color to another as you played. Like they stay all one color, as they are now, but that one color would change every few seconds or so.
In many of the levels there are more than one solution. I wish that the level didn't end as soon as you complete it. I think you should add a grayed-out "Submit" button that becomes active only when a valid path is formed. That way the user can continue to fiddle with the shape until they click the button to move to the next level.
On one level, you could solve it by creating several circles, or one big curvy blob, or some combination of circle(s) and blob(s). You should track how many separate shapes are formed by the user's level solution, and tally them at the end of the game. Keep track of the high score and low score for number of shapes. That gives the game some re-play as the user tries to go through making the most or the least shapes.