Team Fortress 2 was in development in one form or another for almost a decade. Unsurprisingly, the game didn't always sport its now-famous cartoony visuals. In 2003, the alpha build for Team Fortress 2 actually placed the game inside the Half-Life universe. The game pitted humans against aliens, telling the story of the Seven Hour War that was briefly mentioned in Half-Life 2. This would be the war where the Combine quickly took control of Earth.

The game looks bizarre yet familiar. The level is vary clearly 2fort -- Team Fortress' most famous map -- but the riot shields and aliens are pretty jarring. Still, the idea of a Team Fortress 2 that existed inside of the Half-Life universe is certainly interesting. But I think I'll take the version we got.