Via [url=https://store.steampowered.com/news/255293/]the Steam store[/url] and [url=https://list.valvesoftware.com/]HLDS[/url]:

[quote=Valve]- Fixed crash related to KeyValues
- Added 'No Bullets' style for the Paka Parka
- Fixed Widowmaker not giving metal when Spy is disguised as their own team (GitHub fix from Grampa Swood)
- Fixed on-hit attributes not triggering when Spy is disguised as their own team (GitHub fix from Grampa Swood)
- Fixed game mode prefix check failing when loading maps from the Workshop (GitHub fix from LizardOfOz)
- Added null pointer checks for recent casual doors fix (GitHub fix from Bitl)
- Fixed a bug where Gas Passer gas can cover players with gas in spawn rooms (GitHub fix from Bitl)
- Fixed typo in logical expression (GitHub fix from Ian Brun)
- Fixed Vaccinator charge sounds playing multiple times per tick (GitHub fix from treacherousfiend)
- Fixed event text leak in CTFHudPasstimeBallStatus (GitHub fix from Dmitry Tsarevich)
- Fixed Minigun barrel movement being updated multiple times per tick (GitHub fix from Marioiscool246)
- Fixed CHealthAccountPanel not using NegativeColor for negative values (GitHub fix from Bradasparky)
- Improved the random class selection algorithm to reduce the chance of failure (GitHub fix from Bradasparky)
- Fixed KeyValues memory leak in birds (GitHub fix from CosminPerRam)
- Fixed Team Spirit Footprints BLU team coloring (GitHub fix from Herobrine0412)
- Fixed animation playback in the class selection menu (GitHub fix from Hunter Kvalevog)
- Updated Mann Co. Catalog controls to mimic Workshop dialog (GitHub fix from Liam Stone)
- Updated the Globetrotter to fix the second style using the wrong BLU team skin
- Updated/Added some tournament medals

- Updated the Seamann's Stubble
- Fixed the normal map for better shading
- Updated the backpack icon

- Updated arena_afterlife
- Fixed a rare regression bug that could cause players in Hell to count as alive

- Updated koth_dusker
- Fixed being able to build in RED spawn
- Fixed a perch spot outside of BLU spawn
- Added a visual delimitation for the capture zone

- Updated zi_atoll, zi_blazehattan, zi_devastation_final1, zi_murky, zi_sanitarium, and zi_woods
- Fixed an exploit that allowed Zombie Spies to disguise as Survivors

- Updated ctf_doublecross_event
- Took significant steps towards improving FPS on the map, especially around the bridge
- Reduced particle and prop usage around the map
- Removed the ability to roll the minify spell and replaced it with the teleport spell with one charge (Thanks Lizard of Oz)
- Added extensions to the window frames looking through each opposing team's base and made the raised shacks slightly more symmetrical to block Sniper sightline
- Removed the two spell books from just outside of the doors of each base
- Increased the respawn time of the rare spell book slightly
- Added Gargoyle spawns
- Fixed a number of minor visual issues and clipping bugs (Thanks Lilly, The Rat Man, Dr. Maxi, and everyone else who reported these!)[/quote]

Rumor has it:

- Size is ~115 MB