Key Features:

5 New Characters
3 New Weapons
1 New Chapter
2 New Difficulties: Hellish and Practice

Other Stuff

New achievements
Over 20 new items
New abilities
New enemies
New unique room types
A new boss
Gameplay balancing
Trials (Items that make your runs more challenging)
Ultrawide FOV support
Per chapter hue slider (change colour of filter)
Optimisation
New challenges
Save game stability fixes
Crash fixes
Level fixes
Asgard has been tweaked
New rooms added
Raygun charge time shortened
Lighting changes
Little changes everywhere
New floor modifiers
Floor entry blur shorter
Windows darkened in Dark floor modifier
Some sounds tweaked
Gambling machine repurposed