You found the blue key, the red key, and you've killed every single thing that moves, blown up every barrel of toxic/explosive waste, and pushed space bar while facing a wall and heard that oddly sexual grunting noise as the character tries to open a brick wall.
And you still can't find the goddamn yellow key.
Here's the thing, when you spend 20 minutes on one level of a shooter like Doom and others, 15 of those minutes will be spent walking around, shooting nothing, listening to the music that you never really noticed before and now hate like poison.
I don't know about the rest of the world, but I play shooters to shoot. That's why they're called first-person-shooters and not first-person-key retrievers.
And how long is this reality supposed to hold up? Isn't this supposed to be some kind of working military facility? How did people get around here before? Did they all just get to work, go to a keyboard and type in "idclip" and hope that they never tried to walk through an outside wall because then you were lost in a really graphically annoying limbo?
There should be a code you type in where after not shooting your weapon for 20 minutes, a text pops up on the screen that says, "Oh, wait. You just found the yellow key in your OTHER pocket" and then the goddamn thing shows up on your inventory.