Just finished this, great game! Super comfy.
I did run into a potentially nasty bug with file copying - I misclicked and told the game to copy a save file to itself. Rather than doing effectively nothing as you'd expect, it instead saves a zero byte empty file in place of what used to be the selected save. Then the game can't parse the empty save file, which makes it crash at the save select screen, both immediately after the copy and every time the game is restarted, making it impossible to reach gameplay.
I was able to stop the crashing by deleting the empty save file from my disk manually, and luckily I had another current save file so I didn't lose any progress.