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

Birth of the 13th Being, Evil God Serpens
Light came from darkness, and that light split into 12 different divine beings.
The 12 beings that rose from the void shared their powers to create Traum and lived
peacefully amongst their descendants. The descendants prospered under the blessings of
the 12 beings who were now worshipped as gods. But one day, an unexpected being,
Evil God Serpens came into existence.



Main Features

UNCHANGED - The fun of Hack & Slash comes from annihilating countless enemies at once.
As a genre where character growth is tied to devastating enemies to obtain new items,
the focus was set upon the proposition to "gain strength after wiping out enemies" during development.
Stirring away from the typical growth system, players will be able to enjoy
completing their own unique builds.



UNDEFINED - Freedom to Select Various Combat Styles
There are no defined classes in UNDECEMBER.
Once a character is created after customization, players will be able to
freely change around gears and skills based on personal playstyle.
Builds are divided into Strength, Dexterity and Intelligence types, but there are no gear or combination restrictions.
Players are free to cast magic with a sword or summon minions with a bow,
or create any new unique builds of their own.

UNLIMITED - Infinite Combination of Skills
Runes are classified by Skill and Link Runes. Link Runes assist the effects of Skill Runes.
These Runes can be equipped in a separate space called the Rune Cast,
and can be obtained through farming or by completing quests.
Each Rune has levels and grades, which can be upgraded with
materials obtained through farming.

UNSTOPPABLE - Never-ending Choice of Contents
- Acts: The main scenario of the game.
- Chaos Dungeon: End-game content available after completing the main scenario.
- Boss Raid: A cooperative content with up to 8 players.
- Crusade of Glory: A free-for-all PvP content.
- Guild: Gather up to 50 members to gain exclusive benefits such as Guild Buffs.