Don't know what is Stronghold? Then I tell you!
Description:You know Doom, it is always the same, get some weapons, infiltrate the destroyed UAC base or demon hive, kill all the monsters and hellspawn and find the exit switch. This was Doom... until now: Stronghold is a mixture of Unreal Tournament's Assault mode and Skulltag's Invasion mode. Defend your Stronghold against hundreds of monsters, divided into several waves. Earn points, get rewards between waves and let no single enemy pass!
Taken from Realm667.
What do I need to play it?Doom II of course and GZDoom or Skulltag.
What else is in it?40 maps (35 maps + 4 secret maps + 1 intermission map)
Also you can find out more information about the power-ups, arsenal and other stuff here: http://forum.drdteam.org/viewforum.php?f=124
Where I can get it and how much space did it requires?You can download it: http://stronghold.drdteam.org/
The .zip is 146 MB and uncompressed it's 150 MB.
Other info:Since it is said that it runs with skulltag but actually it's a bit buggy in it. So if you want to play it (at least normally) download GZDoom(http://grafzahl.drdteam.org/page.php?page=230).
I suggest to give it try (mainly Doom fans) it's an amazing new and hard experience!