Some improvements could be made...
Graphics
The graphics were alright. I quite liked the background colours etc. But the graphics of the squares coming in seemed pretty poor and the green around the line you drew again looked pretty poor.
Gameplay
I quite liked the idea behind the game. Yet it wasn't executed so well. Sometimes you would draw a loop with your "wire" yet the game didn't sense that so you had to draw it again.
On another note, the game simply wasn't fast enough. I feel asleep after the second level and gave up as it took ages just for the sqaures to get away from the edge so i could draw them again.
I would like to see you make another version of this, a little faster and with some cool new features and the testing of the circle improved. I think a cool feature you could add is a limited "length" for the "wire", so you can't just circle the whole lot.
Graphics 5/10
Gameplay 6/10
Sound 5/10
Overal 6/10