In all seriousness I've only seen a couple of fanmade games in these forums:
-One of them was a 3D version of Abe's Oddysey with its own levels
-The second one was my own flash game inspired by Abe's Oddysey, which I suppose I could provide the source code for if someone really wants it as it's no longer being developed.
It's pretty basic but it has the following features:
*Blue protagonist that can quietly sneak and hoist up ledges
*Guards that patrol back and forth, reacting to the player's noises and shooting the player if spotted
*Dark areas where the player can hide in front of the guards
*Level editor for the standalone version that exports and imports levels in individual xml files
It does not feature things like slogs, paramites, scrabs or possession but it's better than nothing
