I'm planning to make a 2D platformer, so I've been revisiting some acclaimed ones like Donkey Kong Country, Super Mario Bros. 3, Rayman Origins/Legends, Celeste, and others. However, while it's good to know what to aspire to, it's also important to know what to avoid.
So I want to ask what everyone's picks are for the worst platformer(s) ever. 2D would be preferred, but 3D is good and well too. Give me some absolute stinkers.