Really cool concept, i also like the blue and red walls, but there are a few things you could improve:
1. I think the game is too difficult. I couldn't get past level 3 (how?) So maybe let your game be tested by friends or family members before submitting it.
2. The trail looks a bit weird and it doesn't immediately disappear when you shoot the ball. Also, i think you should add that you can shoot the ball with the left mouse button.
Other than that, cool game, but it was too difficult for me.
I hope the feedback helped you a bit, and it would be cool if you could check out my submsision too. Thanks :)