Most of my review will mostly just be parroting what Mindcap said in his video about the level, so I would watch that before delving into any reviews on Limbo. The song is represented perfectly, and the key gimmick is one of the best gimmicks in all of GD, the amount of suspense built up whilst falling into the spikes at the end of the level is utterly unique and makes watching completions of Limbo interesting even for the viewer, as no key combination is the same for any given attempt. This level is popular for good reason in my view.