Quake is a special game. There isn't a deep story or anything, but the gameplay is so well crafted that it instantly becomes hypnotic. One thing that is still impressive to this day is the level design. There are many shooters from the 90's that have confusing and frustrating mazes for levels, but Quake's levels are quite elegantly designed as long as you keep exploring, you will never get lost. It is also not too long; I beat it in two sessions, so if you've never played it, go for it.