SlackBuildsOrg/games/hexen_demo_data

Game data from the demo release of Hexen (hexen.wad, v1.1). Includes
only the first 4 levels of the game.

You'll need a Doom engine that's capable of playing Hexen to use this.
zdoom will work; prboom, prboom-plus, odamex, and skulltag won't.