will i been playing this game pass 2wks now.
there are whole serials I planning buy all of them, basic its Resident
Evil Serials, there no story line to this game, you can play with other by LAN, Internet with other players
L4D 1 & 2
No story line, no maps,
limited to real life you running around trying Stay Alive with three other. it has Co-op too, you can use Steam Players/ friends members to with you invite with you too, like Delta Force game come playing with other players
source:
https://store.steampowered.com/app/550/Left_4_Dead_2/
note its really cheap now dirt cheap too