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.
Once upon a time, there was a peaceful world called Sarasaland. In this world there were 4 kingdoms named Birabuto, Muda, Easton and Chai. One day, the skies of Sarasaland were suddenly covered by a huge black cloud. From a crack in this cloud, the unknown space monster Tatanga emerged to try to conquer Sarasaland. Tatanga hypnotized the people of all the kingdoms so that he could control them in any way he liked. In this way he took over Sarasaland. Now, he wants to marry Princess Daisy of Sarasaland and make her his queen. Mario came to know of these events, and he has started on a journey to the Chai Kingdom where Princess Daisy is held captive, in order to restore peace to Sarasaland. Can Mario defeat Tatanga, release people from his interstellar hypnosis, and rescue Princess Daisy? It's all up to you and Mario's skill. Go for it Mario!