Super Mario Land X - Hard Mode is a modified version of Super Mario Land X, presumably increasing the difficulty. This version maintains a connection to the original game, meaning this is likely still a fan-made creation.  Increased difficulty might involve tweaked enemy placement, enhanced enemy AI, or additional challenges.  As with the original game, definitive development and publishing credits are unknown.

Super Mario Land X - Hard Mode

Super Luigi Land 2 - 6 Golden Coins