The Sun and Moon

System Eight consists of levels 111 - 120 plus boss level VIII. Remember that there is no time limit for completing levels for this achievement, so take your time so you don't die needlessly over and over.

System Eight starts off with five relatively simple levels, with just some precise phasing. The second half of the system has levels that autoscroll, with a black border that kills you if you touch it. These have no room to stop and think, you're just going to have to try them over and over to learn them. The boss battle is unique and difficult at first because you only have a round section that you can move in, and you can't see the rest of the level. You'll have to do some exploring to find all the dots, but then the level is pretty simple. 

Upon completing all 10 levels and boss level VIII, the achievement will unlock.