Cosmonaut is a Half-Life Two: Episode Two mod that recreates the style of game-play from the Half-Life series whilst providing a variety of locations to explore as you encounter Combine Soldiers, Antlions, and a wide range of other enemies. The mod sticks to the formula that worked in Half-Life Two in the hope that it is fun to play, and brings about many nostalgic memories. The mod is set on earth with a very loose premise. You play as a cosmonaut who has had to abandon their space station, but upon arriving back on earth, discover that the place has been overrun by the combine. What happens next? Do you give in to the Combine army, or do you resist and use your skills to find some way of escaping? The mod was initially made for a mapping challenge that took place on RunThinkShootLive.com, called NostalgiaVille. After the challenge had been released, the current maps where updated and new maps where created to give some closure to the mod.
Here is the launch trailer for Cosmonaut.