The first outing for Samus set the tough precedent for the rest of the series to follow with near perfect level design as players are required to think laterally and look vertically in order to progress. The graphics remain the same apart from a palette overhaul. But it was never graphical prowess that sold the Famicom version of Metroid, more delightfully thought out levels that make it a pleasure to play. Unless you're in charge of the series' sequels that is...