1. Set in the Half-Life universe
2. Three new weapons (plus the weapons of Paranoid)
3. Several new enemies (plus the enemies of Paranoid)
4. Fourteen new maps (plus TITLEMAP)
5. Over a dozen new music tracks
Spoiler:More screenshots at DooM Nexus.
Video Trailer (Courtesy of Daniel "Tormentor667" Gimmer):
NOTE: You will need Paranoid.pk3 and GZDooM v2.4.0 or higher to play Paranoiac
Known Issues: Several maps have minor visual glitches when the game is played in GZDooM v2.4.0 with hardware acceleration of graphics. These typically arise when there is a sloped sector under a 3D floor. The texture of the sloped sector and/or its sidedefs get "blacked out". Does not affect gameplay. These visual glitches generally diappear in GZDooM 2.5Pre-232-GF48AF60 (2017-03-31), although the sloped under-liquid areas of Maps 21 and 23 still show this glitch. If this bothers you, when you come to these areas temporarily switch to Legacy or Software sector lighting mode in your Display Options Configuration for OpenGL Renderer. Perhaps future versions of GZDooM will address this problem completely.
Text file for Paranoiac
Important information to play Paranoiac