Did I mention there is a huge maze towards the end of level 8? It's twice the size of a normal level put into one portion of the level! However you must be VERY careful, for it took me several hours to beat.
Levels 1 and 2 are easy. Levels 3 and 4 are meh. Levels 5 and 6 are hard. Levels 7, 8, and 9 are very hard and you need to be and expert gamer to beat them.