Here on itch- search for RPA Extract (by iwanPlays) and download it (should be free).
In FBtW's folder, go into the folder called 'game' and locate 'images.rpa'. Drag that onto RPA Extract's .exe and 2 folders should generate in the same folder as the rpaExtract.exe- 'gui' and 'images'.
All sprites, illustrations and backgrounds will be in the 'images' folder.