One of the greatest classics!
Well, at the time of release, Flashback was a masterpiece in every way. It had some of the most innovative gameplay, incredible graphics (for the time being, anyway), great sound and even an awesome story.
It's kind of hard to describe the genre. It features elements of puzzle, platforming and action - a mix of them all, if you can put it that way.
You start off as a man named Conrad. He doesn't remember what has happened to him or where he is. So you follow his journey through very different places as he works his way to find out what happened.
Flashback is definitely something everyone with respect for classical gaming should play.