Summary pulled directly from Steam - Some text may only be applicable to Steam platform

Steel yourself as you travel through Vesper's first Mirror of Mystery and bring a merciful end to an ancient god!

Eons ago, the Coiled got the biggest catch of all: an Old God! They trapped the being within the sharp-toothed, leathery-skinned body of a mighty seawarg, caging it deep within an icy mountain. Only you have the power to free the humiliatingly named "Chums" from his fleshy prison—but doing so means wading through wintery wastelands, arid ruins, and flooding caverns full of enemies. You're caught in the middle of a raging battle between slithering Coiled and angered denizens of the briny deep. The only way out is through.

• New boss "Chums" the Old God, with four powerful forms that unlock over time
  
• New loot to collect, including weapons, gear, and cosmetic items
  
• Additional environments that, when beaten, can show up in the randomized endgame dungeons of the Chaos Chamber