Epic Games' Unreal is 20 years old, and to celebrate, the game is available for free, with all expansion packs included, from GOG.com or from Steam! Hurry though, you only have 48 hours from the time of this article going live to claim your free copy....

Unreal was arguably one of the major milestones in the evolution of the FPS genre. It pushed the technical envelope,  both graphically and in terms of gameplay, with it's open maps, enhanced combat and atmospheric soundtrack & cinematics.

It was also the game that launched the now infamous Unreal Engine, with UE4 currently being one of the most popular game development tools, the legacy of this game is felt even today.  It even made it into the Guinness Book of World Records.

There are also heavy discounts on other Unreal games, such as Unreal 2, Unreal Tournament GOTY, and my personal favourite, Unreal Tournament 2004: Editors Choice Edition, with the whole lot beimg available for just $5.97.

And if you're looking for some cool mods to go with your new freebie, then our sister site ModDB has a round up of the best ones here.