Valve was founded in 1996 by former Microsoft employees Gabe "Gaben" Newell and Mike Harrington, and became a well-known developer with their first game, Half-Life, before focusing primarily on PC gaming. Portal happens to be a spin-off of the Half-Life series, which is made clear through the mentioning of Black Mesa in Portal, the fictional company that Half-Life protagonist Gordon Freeman works for.
- A common running gag among gamers is that Valve, more specifically its managing director Gabe Newell, is not able to count to three. This is a joke that refers to the notrious cliffhanger ending of Half-Life 2: Episode Two, a game that was released back in 2007. Many fans have been waiting ever since for a Half-Life 3, but no such news has ever been announced to this day.
- This running gag became even more notorious when fans noticed that every franchise by Valve only has two games, including Portal.
- The lack of such a game could possibly be due to the company trying to focus more on its Steam program.
- Ironically, even though Valve is known for working primarily on games that are exclusive to PC platforms, LEGO Dimensions is not available for PCs, despite the fact that its main competitor, Disney Infinity, is available as a digital download game for PCs in which player characters can be unlocked by entering a code included with each figure or playset that will allow access to content on your Disney account.
- Since LEGO Dimensions was released for the Wii U it marks the first Valve game and first Portal game to appear on an Nintendo platform.