The Polygons really need a speed limit and please remove the bounce on the bullet. That bounce personally killed me more than it hurt the enemies and it adds an unnecessary level of difficulty to the game which already progresses in difficulty considerably level by level.
I disagree, the bouncing is fun! Once you learn to control it, it's very useful too. I do agree on the speed limit, however. Perhaps they could not have an explicit speed limit, but instead make it harder for them to pick up speed the faster they go?