Is there a way to end the game? The game froze as I killed the final boss and when I loaded back in it was dead, but there appears to be no way to trigger ending / submitting high score?
That shouldn't happen. See if there is a folder called logs created in the same location as the game, there should be a crash log inside it.
If you send me your save file, I'll see if I can submit your score for you. I just found the bug. Your save file can be found in C:\Users\[name]\Forest RL\save
Contains log file (it created a bunch of them and they were all idential and made at the same time) and it contains the .dat file https://www.dropbox.com/s/w34xc1tw3d4uf78/fr_files.zip?dl=0