Quake 2- Unseen - Gameplay
Quake II - Unseen was a commercial add-on project for Quake II being developed by Tequila Software in 1998. Originally called a "mission pack", in the style of the officially sanctioned add-ons in the Quake series, the suggestion that it was authorized lead to legal action by id Software. Ultimately it was resolved to refer to it as an "expansion pack" instead. In the end it never saw commercial release, being put out as a free download online. Owing to how it was created, it is only playable using the original Windows 95 version of Quake II, and none of its commercial or source ports.