Cuphead

Studio MDHR animated this the way Fleischer and early Disney shorts were made — hand-inked cels, watercolour backgrounds, deliberate 1930s rubber-hose distortion — and the production reportedly cost the founders their houses. The result is a run-and-gun that is really a boss rush: a handful of side-scrolling stages sit between fights that make up the bulk of the game, each a multi-phase pattern test where every phase transition changes the arena. It is hard in a specific, fair way, with a parry on pink objects, swappable weapons and charms that meaningfully change approach, and death is instant enough that retries feel cheap. The 2017 release is worth playing for the presentation alone, but the fights hold up independently of it; several are among the best-designed boss encounters of the decade. Everything you see was drawn frame by frame, which is why it has not dated and will not. The Delicious Last Course expansion added a new island, a playable third character and a set of fights harder than anything in the base game.