It's a remake of Super Mario Land! Made using the same engine Perennial uses. It runs a lot better than the gameboy version, and has some neat features, 4-player couch co-op, parallax backgrounds, joystick support, wide screen support and high refresh rate support. The graphics have been improved slightly. The goal was to recreate the game how you remember it, not how it was or how it would have been on a more modern system. There is also an option to make it look like the original gameboy graphics, complete with greenish tinge and pixel grid.