There are some (relatively) impressive games for the Master System, but I think that's because it stuck around into the nineties, in regions where there was an installed base i.e. not the USA. Late-generation games often benefit from better optimisation, and things like more cartridge space. The Master System port of Mortal Kombat, for instance, despite being pretty horrible as a game, is miraculous from a technical point of view. Despite being heavily cut-down, of course, it was an attempt to create the same game. That's a port (or demake or whatever else you'd want to call it) of a 1992 arcade cabinet, onto a home console released in 1985.