Scoobes on 27 February 2016
Such a difficult question to answer. There are so many.
For giving the player numerous ways to approach a level:
Deus Ex, Deus Ex: Human Revolution, and Dishonored
For introducing and exploiting new gameplay mechanics as you progress:
Metal Gear Solid, virtually every Zelda game since A Link to the Past, Metroid Prime, Portal 2, Half-life 2
