Current Events > Overly complex, yet simple classic games?

(+) Yeah! (+)

Old games that had simple concepts, but were very complex and deep when mastered.

For example, X-Multiply. It was a sort of spinoff of R-Type. Same basic gameplay, except instead if the pod, you have two tentacles. They can be wrapped around your ship as a shield, and you control the tentacles with your momentum. It is weirdly deep and complex for such an old game, and parts of the game practically demand that you shield yourself and take a defensive stance against tons of undodgeable bullets.

The game is really simple otherwise, but the tentacles add another layer to the game.