How do you unlock each of the stages?

I've managed to unlock one stage (Towerforge) by playing through the entirety of Quest mode.

A friend has told me that he got one randomly by selecting random in the stage selection, and another by the end of a versus match on a specific stage.

What are the definite ways to unlock these stages?

Solution 1:

I'll update this answer as I unlock stages:

• Sunken City: Choose "random" at the versus mode stage selection, it will come up eventually.
• Towerforge: Beat King's Court in Quest mode on any difficulty.
• Moonstone: Play a match on every non-unlockable level in versus mode, then play a match on Sacred Ground.
• Ascension: After unlocking the previous 3 levels, go to archives and find the Ascension tab. On each of the 3 stages you can find hidden direction symbols in the background which make a code you can input.
  • Final code: Right Up Left - Right Right Down - Down Up Down.

Quest Mode-only Stages:

• Gauntlet: Beat Ascension in Quest mode.
• Gauntlet II: Beat every level in Quest mode on hardcore difficulty.