Here's one I never thought I'd see. Apparently the Serious Sam modding scene is pretty wild though! Someone named Nekorie over on Steam has created a full conversion mod of the game, turning what is usually a violent arcade shooter into a peaceful G5 based platformer. It's sup;er impressive, starring all the ponies fully modeled with dialogue and quests across 2 areas.
Check it out on steam over here. There's also a video of it in actionk below.
