Enemies as Palette, Not Characters

5. Enemies as Palette, Not Characters

With tiny memory budgets, you couldn't author unique behavior for every enemy. Instead, designers built a small "verb palette" of enemy behaviors (patrol, chase, shoot, block) and reused them with re-skins and recombination.

Rule of thumb: Design 4-6 enemy behaviors, not enemy characters. Then get variety by combining behaviors and placement, not by writing new AI. (This is literally how Mega Man, Contra, and Metroid get so much mileage from so little code.)