LEFT 4 DEAD

Have you ever wondered what life would be if there was a zombie apocalypse? Well this game will
make you realize what it feels like!

This game is a cooperative first person shooter , arcade style game where you need to survive against countless hordes of zombies... Yes.. ZOMBIES.

GAMEPLAY:

Left 4 Dead is a first-person shooter. In campaign mode, the player takes control of one of the survivors; if four human players are not available, then the remaining survivors are AI-controlled bots. They play through the levels fighting off the infected—living humans who have been infected with a rabies-like virus that causes psychosis. The survivors are carriers of the disease, so they do not show signs of any symptoms.

Counter Strike

OVERVIEW:

Counter Strike is an awesome first-person shooter game developed by Valve , It originated from the game Half Life which is also awesome btw. This game has been a huge huge success since its release. We can say that because up until now it is still going strong. There are only few games that last more than a decade, and This game is one of them
-XYZenon

GAMEPLAY:

Counter Strike or lets just say CS is a game composed of two opposing teams. The "Counter-Terrorist" which is basically the good guys, and the "Terrorist" the bad ones. The Counter-Terrorist team's goal is to stop the Terrorist from bombing the "BOMB-ZONE" and rescuing the hostages from them. vice versa, The terrorist goal is to get to the bomb-zone and plant a bomb there, or just defend the hostages till the time is up.
If ever that one team is completely annihilated,  the round is over and the other team wins. The game will start again and so on and so forth.

If ever my explanation does not suffice, here is some from our dear friend wiki

"DOOM" The very first game I played on PC

According to Wikipedia:

Doom  is a science horror-themed science first-person shooter game by "id Software".

In Doom, YOU( players ) assume the role of a space marine, who became popularly known as "Doomguy" I dont know why He is called that but, fighting their way through hordes of invading demons from Hell.


The Doom franchise was later continued with the follow-up Doom II: Hell on Earth (1994) and numerous mission packs, including Master Levels for Doom II , and Final Doom .

 Originally released for PC DOS, the games have later been ported to numerous other platforms. Once the game's source code was released in 1997, it spawned even more adaptations, as fans further ported the code to countless devices. The series started to lose mainstream appeal as the technology of the Doom game engine was surpassed in the mid-1990s, although fans have continued making WADs, speedruns, and modifications to the original.

DOOM WIKIPEDIA