Super Mario Land 2 is one of the more underrated games in Nintendo's library, with a suite of interesting ideas and some truly weird levels. It was even the first Mario game to let you go to the moon. And now it's in colour.
Thanks to ROM hacker toruzz, you can now play a sleek, colorized, lag-free version of Nintendo's 1992 Game Boy game. Fun fact: This was Wario's first appearance in any video game. Nintendo director Hiroji Kiyotake liked the greedy, fat villain so much, he made him into the protagonist for the sequel, Wario Land: Super Mario Land 3. Which is also a top-notch platformer. But we're digressing.
You can check out the ROM hack here.