SM64 Green Demon Challenge (IngoH Version) is a ROM hack of Super Mario 64 for Nintendo 64, known for its high difficulty. Super Mario 64's original gameplay involved exploration and collecting stars. This hack, however, significantly increases the difficulty by creating challenging custom levels and/or modifying existing ones.  IngoH is likely the creator of this particular version of the hack. It focuses on intense platforming skills and precise movements.  The objective might center around completing the challenging levels or possibly beating the Green Demon enemy. This is an example of the fan-made content produced by the ROM hacking community.

SM64 Green Demon Challenge (IngoH Version)

SM64 Castle Remix