This was a pretty good game. It didn't have that many parts that were that unique. On the same note, it didn't really have anything wrong with it. Maybe there could have been more detail with the enemies. It's pretty fun to just destroy these things over and over. 15 levels sounds like a good enough number.
It's nice to have all these powerups. A pity you don't keep them when you go to the next level. For the most part, this was good. While not great, the sounds were fairly good and fit the style. There didn't seem to be any problem with the synching.