Slightly expanded version of Thief: The Dark Project with three whole new story missions and one blooper reel mission. Still contains the entire game, and Song of the Caverns along with the Blooper Reel are fun additions. Song of the Caverns is probably one of my favourite Thief levels, to be honest, so inventive and atmospheric and definitely an inspired choice to set a Thief level in [REDACTED]. Mages' Tower is pretty good although it does become inevitably linear towards the end, and Thieves' Guild is uh... sort of map where it seemed way better in concept but in execution just becomes needlessly convoluted. CTRL+Alt+SHIFT+END is your friend if you don't want to play certain missions.

Also uh, the Blooper Reel. This can be accessed by opening up the USER.CFG file as a text document and adding "starting_mission 16" onto it, then start a new game. Is pretty interesting, sort of is a showcase of various bugs that happened during development and people messing around with the game engine etc. Has the feel of a shitpost Doom WAD.