Korsakovia - A single-player mod for Half-Life 2.

The game acts as a side story to the movie where the player takes the role of the park's game warden, Robert Muldoon.

Jurassic Life - A modification based on the first Jurassic Park film.

Flipside - A side-scrolling platform game that allows the player to 'flip' the game world around to its backside, altering the means a player can traverse a level.

Dear Esther - An experimental 'ghost story' created as a research project at the University of Portsmouth initially released as a free modification in 2008, a longer commercial version was developed and released in 2012.

Coastline to Atmosphere - A mod set in the Half-Life 2 universe, following Gordon Freeman after the events of Half-Life 2.

Black Mesa - A recreation of Half-Life using the more advanced Source engine.

Instead of a portal gun, the player solves puzzles using a mix of these gels that they can spray onto surfaces with a tool they carry.

Aperture Tag - A modification based on Portal 2 that recreates the essence of the game Tag: The Power of Paint, the inspiration for the various gels used in Portal 2.

Portal 2 mods steam