Knuckles' Emerald Hunt Mania
Parent game
Sonic Mania is a side-scrolling platformer that pays homage to the original Sega Genesis Sonic the Hedgehog games. Players choose from Sonic, Tails, or Knuckles, each with unique abilities, and speed through 13 zones that include redesigned stages from past games alongside original levels. The game features special stages for collecting Chaos Emeralds, time attack with online leaderboards, and split-screen competitive multiplayer.
Could be interesting
A fangame for the unlikely run 'n' jump series Giana Sisters.
SM64 GBA is a non-profit fan project which aims to make a port of Super Mario 64 (along with new features, like new characters) for the Game Boy Advance. The project was started as a means of testing and improving how 3D games can be developed for the Game Boy Advance architecture, a capability that only a few commercial games made use of. The game is still in development, but isn't currently intended to be released officially by the creator.