This patch is a quick hotfix to deal with a few major bugs that snuck into the previous update, along with a couple other minor adjustments, including new vsync modes you can try if the original method was causing slowdown and turning it off was causing tearing.
Patch Notes
Bug Fixes / Adjustments:
Major / Crystal Dungeon: Fixed a new 1.2.1 exclusive issue where there was now an invisible wall when returning to the final room of the dungeon
Major / Water Dungeon: Fixed a new 1.2.1 exclusive issue where the entrance door would shut behind you when revisiting the dungeon
Boss / Ending: Fixed a bug that would allow you to easily bypass the final boss's new gimmick from the previous patch
Settings / Display: Added 2 new vsync modes. Test them out if you are having screen tearing but the default vsync mode is running slow.
Menu / UI: When opening the menu while playing as Reima, her cursor is now aligned better
Ending / Major: Dying and retrying during the ending now has better and less buggy checkpoints
Mapping Adjustments:
Lightning Dungeon: Some mapping cleanup was completed
Lightning Dungeon: Every room now has the lightning effect
Beta Branch Only:
Minor / Localizations (beta branch only): A couple small mistakes in the Japanese localization text were fixed