Valve released Portal 2 in 2011, and that’s the last time players returned to the Aperture Science Enrichment Center, except as a backdrop for demoing new VR tech. The dream of exploring beyond the end of the second game has been kept alive, though, thanks to mods.
Sometimes, it’s what outside of a level that’s really interesting.
Doug “Rat Man” Rattmann is one of the most important characters in Portal, though he didn’t appear in either game. The message-scrawling scientist made his video game debut in LEGO Dimensions’ Portal level pack, though he’s so well hidden it took more than a year to find him.