All kinds of retro games; including but by no means limited to 2D shooters, platformers, and 'chase' games such as Pac Man, Mr Do, Dig Dug, etc. Old arcade games fall into this category by definition.
Everyone is busy getting all 'high definition' with their 360s, why would they want to play ancient old games with pixels the size of bricks? There are good reasons - reasons based on fun.
