Sven Co-op is described as 'Online co-op game based on Half-Life'. There are five games similar to Sven Co-op for a variety of platforms, including Windows, Linux, Steam, Mac and Xbox. The best alternative is Half-Life. It's not free, so if you're looking for a free alternative, you could try Hexen II. Other Sven Co-op like games are Doom (Paid), Quake (Paid) and Black Mesa (Paid).
Half-Life is a science fiction first-person shooter video game developed by Valve Software, the company's debut product and the first in the Half-Life series. Represent entire series of Half-Life games including Half-Life, Half-Life 2.
Doom is a science fiction horror-themed first-person shooter video game in which players assume the role of a space marine, popularly known as "Doomguy", who must fight his way through the hordes of invading demons from Hell. Represent entire series of Doom games including Doom , Doom II: Hell on Earth, Final Doom, Doom 64, Doom 3, Doom (2016), Doom Eternal.
Quake is a series of first-person shooter video games released by id Software. In the game, players must find their way out of various maze-like, medieval environments while battling a variety of monsters using a wide array of guns. The successor to id’s... Represent entire series of Quake games.