What does the full version add compared to Early Access?

The full version includes numerous balance improvements and fixes based on your feedback. In terms of content, version 1.0 introduces:

A Fallen Hero – Kinslayer: A new playable character ready to carve a path of vengeance.
Helheim: A brand-new, dreaded underworld region filled with puzzles and a linear path, only the bravest heroes can uncover its secrets.
Endless Mode: Survive the perils of Helheim to unlock a challenging new mode where you face overwhelming odds and carve your name into legend.
Godly Support – Nidhogg: A merciless, massive dragon who tears through enemies