x2i136,878 Locked 10 Jun 2009 10 Jun 2009
The 5th and 6th levels of the game are the Marble Garden Stages and they are a bit high and low, it is also very fast and sometimes tricky so just take your time. You have the advantage of a save feature that you can use to save your progress at any point in the game so if there's a section that you think you're going to die, save it and then attempt and if you fail, re-load the game save.
Simply complete these two acts to get this achievement.