Sure!
- Navigate to "C:\Users\[your username]\AppData\LocalLow\ScarletPaper\ThornSin
- In this folder, you'll find a save file named gamedata00.save. This is the save file you need!
- Create a new folder as a back-up and call it whatever you want.
- Whenever you reach a new room, gamedata00.save gets updated. This basically means that you can create copies of gamedata00.save, and place these in the backup folder (after renaming them). You might want to copy save files (1) when you reach a new level/stage, (2) when you're in a room with an enemy whose scene you want to replay, (3) just before a boss room, (4) just before a new scene with the merchant
For instance, let's say we're in the room before the first boss. You copy gamedata00.save and paste it in your backup folder, and rename the save file as, e.g., first_boss.save. Later, when you want to replay the scene, rename first_boss.save to gamedata00.save and replace the original gamedata00.save. Afterwards, open the game, load the save file and you should be back in the room before the first boss!