Good, simple, frustrating.
I enjoy this game. It's a lot of fun once you get the hang of it. Reds push it, blues pull it, try to make it land in the goal. You may want to add some sort of 10sec tutorial just for people who dont like trial by error. Add a hint kind of thing for the higher levels too, i donno.
One thing that really bothered me was that sometimes i would get the ball to land in the goal and it wouldnt count as a win. On Transporter level, i got it to go all the way through everything and it landed in the goal, but it won't count as a win. It's annoying on levels that require you to time the release just right.
I still enjoy the game though, just needs some tuning.