Intense firefight with alien creatures — Half-Life: MMod

Reelism 2 is a mod that transforms Doom II into a chaotic wave shooter where players face 60-second waves of enemies. Each wave is determined by three random "Reel" effects: for weapons, enemies, and general conditions.

BorderDoom is a mod for Doom that combines the dynamic action of the classic shooter with RPG elements from Borderlands. Weapons with random stats, rechargeable shields, leveling for players and monsters, progression, and loot make each playthrough unique.

Half-Life: Field Intensity is a large-scale modification for Half-Life that adds a new campaign and covers events from the arrival of the military at the Black Mesa research facility to the nuclear explosion, offering an alternative perspective on the disaster.

Hard-Life is a mod for Half-Life focused on increasing difficulty and reworking gameplay. Enemies become more aggressive, intelligent, and deadly, while their usual placement is changed so that even experienced players must constantly stay alert.

C&C Red Alert 2: Reborn is a mod for Yuri's Revenge that adds 19 countries, dozens of new units, as well as super units, improved but crazy AI, and a mass of original maps. Despite questionable balance, the mod is known for its fun and chaotic gameplay.