The 2 Most Important First Person Shooters Ever Made!

https://en.m.wikipedia.org/wiki/Oper...old_War_Crisis

https://en.m.wikipedia.org/wiki/Tom_..._Six:_Lockdown


Cold War Crisis was the first FPS with Air/Land/Sea Vehicles.

Lockdown was the first FPS to have both Iron Sights and doors you can open/close


Being able to open/close doors might sound silly but if you ever played tactical shooters such as the early rainbow six games, or the SWAT and Socom series, you would know how much doors make a difference in gameplay.

I also think it's essential for a FPS to have Iron Sights, without it I think it defeats the purpose of the game being in first person.