Killing Floor (UT2004)

Killing Floor is a mod for the Unreal Tournament 2004 video game, first released in 2005 as a demo, and full version, later that year. The mod acquired popularity after appearing in several game magazines. It is a survival horror first-person shooter based game, with Co-op multiplayer action. A retail version of the game was released via Steam on May 14, 2009. The mod is now unofficially updated by The Miasma, and they are also hosting servers.

Gameplay
Killing Floor's Gameplay is comparable to the Invasion gametype. Designed around co-op (Cooperative) play, it puts people against a city of millions of infected people, primarily based in the United Kingdom, with weapons ranging from pistols to explosives. Players must arrange their group to most effectively counter the waves of enemies, including adopting specific strategies such as barricading themselves in, or finding high ground.

The objective is to survive as long as possible against continual "waves" of enemies. The number of enemies in a given wave is a calculation of how many players are left. The number of enemies that they must defeat before the round ends is displayed on the HUD. Upon defeating the required number of foes, the wave will end, and shortly thereafter the next will begin, bringing more difficult foes.

In order to fight off these increasingly challenging enemies, players must acquire money by killing zombies. The amount of money gained per kill depends on the difficulty of the enemy. Money acquired by players can then be spent at the Trader's shop, which opens at the end of each wave.

Equipment
There are 23 different pieces of equipment in the retail version of Killing Floor, including two tools, five melee weapons, pipebombs and an array of firearms. Most of the firearms require manual reloading, with the exception of single shot weapons. As difficulty increases, weapons become more and more ineffective. Weapons and ammo can be found lying around the maps and at the Trader, to whom players will have access to between enemy waves. As a player progresses in the perk system, they develop unique skills and attributes to benefit a specific class and the weapons connected to that class. For example, when a player does enough damage using shotguns and welds enough doors using their welder, they will advance to the next level for their "support specialist" and will increase the speed and effectiveness of welding as well as improving ammo capacity, firepower, and reload speed. There are a total of 7 different perks to choose from and each can be advanced up to level 6.