ZDoom

Alienated is a 10-level wad made for GZDoom and Zandronum. It features levels of varying size and difficulty, all made with the Ancient Aliens texture pack. There are 9 regular levels and one secret map, accessible from map06.

The wad is meant to be played with dynamic lights turned on. Freelook is recommended, but not required. No jumping or crouching. Do not use vanilla or software in the sector light mode settings, as these options can mess with certain tricks used in map08 and ruin the experience for you. 

DOWNLOAD: https://www.doomworld.com/idgames/level ... /alienated

SCREENSHOTS:
https://i.imgur.com/5Td79rF.png
https://i.imgur.com/HDQuTCU.png
https://i.imgur.com/SVr0R8N.png
https://i.imgur.com/7IhSm9Q.png

The project is fully co-op compatible.

Special thanks to:

Ugibugi - for collaboration on map06 and playtesting
Malefication, Hak3180, Immorpher - for playtesting
Elend - for creating the M_DOOM image

Oh my, this looks very nice from the screenshots.
Gotta give it a go soon.

Is the idgames release the same as the RC3 release or have there been further updates?

It's the same. Only the filename was changed.