Killing Floor

The gameplay consists of a single game type, single- or multi-player, in which the player fights through waves of zombie-like monsters (or more precisely, specimens from a failed military experiment), with each wave becoming successively more difficult, moving through each area of the level, until it concludes with a battle with a super-specimen, called the Patriarch.

Parts

Part1: http://www.megaupload.com/?d=A2MOXOGP