Talk:General Info & Hints/@comment-87.79.136.60-20130709225204/@comment-8961248-20130710075445

Features put into a game increase the amount of Tech and Design you generate while making this game.

That's all they do, without consideration of whether there is a more recent one. That means that it is better to put every available feature in your engine except maybe those that are mutually exclusive (see Custom Game Engine for a list)

However since you complete against your previous scores, putting every feature, even though it costs more, allows you to fine-tune every game to be closer to the exact score you want, by enabling or disabling features to control the amount of Design+Tech you generate.