Psycho Waluigi is a Mario fangame by Thunder Dragon that stars not Mario but Waluigi, perhaps the most underrepresented playable character in the Mario franchise.
After suffering a massive bump to the head, Waluigi wakes up in the unfamiliar land of Unconcia, only to discover that he now has psychic powers! In true villain fashion, he decides to use his new abilities to take over this strange new land, one kingdom at a time. Using the Psycho Iris, he can pick up objects and throw them at enemies or mind control an enemy to shoot at other foes. He can also collect coins and valuable jewels along the way to trade for powerups like a double jump and accessories like a shiny gold crown.
This tool-assisted run by sack_bot features precise jumping and a glitch that allows Waluigi to clip into walls.