One thing I really miss from amiga games, as well as other oldies, compared to current games... the music
1: I liked that the music sounded unlike anything you'd get anywhere else. You couldn't turn on the radio and hear something like the intro to Alien Breed.
2: In-game music. Yeah, a lot of games try to be ambient, but it'd be nice to have the option more often rather than just background noise.
3: A lot of games have extremely generic music. Epic sounding movie music for the intro, often very interchangeable. There's no mistaking say, the music of Chaos Engine with that of Turrican.
Obviously there's exceptions but this is something I really miss.