August 17th Small Updates and Bug Fixes

[Update]

1. Add Newgame+ difficulty level mark to clear save file
2. Add Newgame+ progress notification when loading campaign clear save files
3. Release advanced sub-quest level restrictions
4. Replace elf king sound

[Bug fixes]

1. Correcting the phenomenon that the game could not proceed after mass production of items
2. Correcting some challenges that have not been cleared