It's really hard to decide if these first-person-shooters are aimed at the young crowd (under 12), the teens, or the college age crowd...Or even older...
The games I've mentioned here (Doom3, Quake2 & 4, Half-Life & it's sequels), Wolfenstein, and the like all have such advanced game engines that they transcend mere gameplay. Eric reminded me of how fantastically detailed these 'game' environments are, and how much effort is put into the detail of the surroundings as well as the gameplay.
A good example is the use of 'scripted sequences' in the game (not to be confused with cutscenes which are also used). Some are interactive and the player can use them to complete objectives. Moving platforms, trams, vehicles, trains, elevators, and walkways are all scripted and the player can jump on them/get in them and be transported around.
Or there can be scripted sequences that really don't contribute all that much to gameplay or the storyline but are so delightfully detailed that you know that the coder spent months getting the sequence right. One such is the submarine pen in Wolfenstein. Your objective is to infiltrate the sub base and find out where all the scientists are going. In doing so, you arrive at an underground sub pen and witness the submerging and deploying of a sub. You can't stop it (although you can dive in and ride it out) but it is such a huge object and moves so realistically that it is worth re-playing over & over and watching from different angles & heights.
I got to that part of the game yesterday, and was eagerly anticipating the sequence, while exploring all the dead-ends & extra rooms/corridors/cul-de-sacs in the game. When I finally got to the sub pen and turned the final corner...the sub was gone!!!
I was crushed. An hour of shooting Germans and the occasional creature and no sub!!!

An empty dock.

I went back through the level and found out where I had made my boo-boogone wrong - the final door to the sub pen is the trigger for the scripted sequence. I had opened the door without entering and the sequence went on without me. The second time, I got to watch it submerge and start moving through the sub pen doors.
That's an example of a scripted sequence. A cutscene is an in-game movie; gameplay stops while the scene plays. Cutscenes are used to fill in parts of the story not coded into the game, like generals deciding where to send you next. Or to introduce a new creature that is more difficult than what you have encountered so far, so that when the cutscene ends and gameplay resumes, you can quicksave before you get slaughtered...And then you can try different tactics to defeat the creature before getting killed off.
BTW, if you forget to save during/after achieving difficult objectives, and get killed, then the game level/episode starts over from the beginning...Annoying if it's taken you an hour or more to get that far and the level is far from over...
Back in the '90's, 3 or 4 of my buddies & I would get together, either online via WAN or at my place via LAN to play Doom multiplayer. The other games (which came out much later) also have much more sophisticated multiplayer modes. I don't have a fast enough connection to play online but it is a vary big PC 'sport', with national competitions and annual gaming conventions in various cities.
At one time, I got into creating levels for Doom and Quake. But it is quite time consuming, and requires a lot of HDD space. I finally just stopped developing my own and just tested others levels. And hacks. And walkthroughs. And game ports.
I'll see if I can get a screengrab of the sub in Wolf...
OK! Here's the sub; started submerging as I went through the door...
The in-game color palette is much more rich than my Windows palette; so this pic appears grainy and dark...In the game, it is much more rich and colorful...At least, as far as German submarines go...