Donkey Kong Jr.

Donkey Kong Jr. is the only game in which Mario is the villain. Shigeru Miyamoto designed it as a direct sequel to Donkey Kong, and it reverses the premise: the ape is now in a cage, and you play his son climbing through four screens to free him.

The movement is entirely vertical. You climb vines, chains and wires, and the key mechanical idea is that you can hold two of them at once - gripping a vine on each side lets you move between them, which is how you dodge the enemies that come down the same route. Jumps sit between the climbing sections, and the enemies (Snapjaws, Nitpickers and the electric push-buttons Mario controls) each have a distinct rule rather than a shared shape. The four screens escalate from a simple vine climb to a final chain-and-spring ascent, and completing them frees the ape and restarts the whole thing faster. Nintendo released it the year after Donkey Kong, and it is the game in which Mario - then still Jumpman - first got his name on screen, painted on the cage.

• ▸Mario appears as the antagonist for the only time
• ▸Grip two vines at once to move between them
• ▸Enemies with individual rules rather than shared patterns
• ▸Four screens ending in a chain-and-spring ascent