Super Mario Bros

The platformer that established the rules everything since has worked from, playable in a browser. What stands out returning to it is how much of the design is about momentum: the jump arc depends on your running speed and how long the button is held, so the same gap requires different approaches depending on what you did ten steps earlier. That is the reason it still feels good. Nothing is snapped to a grid and nothing is automatic; every jump is a continuous input with a continuous result, which is why the controls are described as tight rather than forgiving. The level design teaches without text — the first screen demonstrates enemies, blocks and height in sequence, and every later stage introduces one idea before combining it with others. It is harder than its reputation suggests, particularly in the later worlds, and there are no checkpoints beyond the stage midpoints. A full run takes an hour or two. It plays with three inputs on a keyboard or on-screen buttons, runs on anything including very old hardware, and is worth playing attentively rather than nostalgically.