Alright, I read some stuff in the forum archives about an idea for an FPS game based on the foundation, and now I've got a bunch of ideas stuck in my head >.> This thread is made with the understanding that this game will probably never be made, but it's still fun to plan.
The other game idea I read felt bogged down back backstory. My concept has the PC as an unknown outsider who wakes up in the middle of a wrecked section of Site-19. This obviously isn't canon, so the game's site-19 will contain whatever SCPs are narratively convenient.
You will use SCP-127 as your primary weapon, finding it on the ground near where you wake up. (Later you might have to avoid shooting it in the presence of Foundation staff because they would confiscate it.) The games 127 differs from the canon 127 in that it rearms significantly faster, and can be reloaded by collecting human teeth (which, in the ravaged site-19, will be fairly easy to obtain from corpses) The gun make disturbingly un-gunlike noises, including quiet breathing and the occasion muffled vocalization like 'huuuunnngry' when you're out of ammo (it should also tell you to kill people every once and a while.)
You then have to fight your way through the ruins of site-19 to reach an undestroyed section. And by fight, I mostly mean run like hell. Your gun will take out zombies and D-class but shooting at most SCP-items will waste your ammo and get you killed.