Defence Alliance 2

There are many examples of mods that became as famous as originals or even exceed them in popularity. Apparently, this is the case of Defence Alliance 2 — a community-made mod of the well-known Killing Floor. This is a classic tactical first-person shooter at its core. The gameplay is built upon attack and defense scenarios and requires good strategical skills to complete missions before time runs out. The objective of the attacking side is to defeat an opponent's firing point. In its turn, the defending party must ward off by placing turrets and rocket launchers advantageously. In-game character classes include Mechanic, Rocketeer, Medic, Rifleman, Machine Gunner, and Sniper. As always, each class is graced with definitive abilities. In combination, these can shift the player's position on a battlefield. DA2 was released back in 2009 and has been supported loosely since then. Despite this fact, it's playable. In the case of crashing, you can find a solution on steam user forums.