Half Life 2

Half Life is a shooter game with a lot of action . You have many levels and some problems are difficult to solve.Try to be creative and find new solutions .By taking the suspense, challenge and visceral charge of the original, and adding startling new realism and responsiveness, it opens the door to a world where the players presence affects everything around him, from the physical environment to the behaviors -- even the emotions -- of both friends and enemies.

The main character is Gordon Freeman who must solve all quests.There are a lot of bad creatures and monsters.Use weapons and fire faster.

The player again picks up the crowbar of research scientist who finds himself on an alien-infested World being picked to the bone, its resources depleted, its populace dwindling. Freeman is thrust into the unenviable role of rescuing the world from the wrong he unleashed back at Black Mesa.

Counter Strike was created based on this game.

Save people by bad aliens . Have a lot of levels and can be played online.