Portal (2007) is a puzzle video game using the Orange Box engine. The game is described as a first-person shooter set in the Half-Life universe. The game operates as a puzzle-based shooter, allowing you to create portals that link to one another on any flat and large enough surface.
The gameplay is similar to Narbacular Drop by Nuclear Monkey Software, an indie game that won the IGF 2006 Student Showcase. Members of the development team who created the game were hired by Valve in 2005.
- Portal (
- Source 2007 shared (
- Source shared (
- Orange Box engine branch