You got a cool idea and a nice foundation for it! The cleaning minigame is neat and overall what we have is not bad, just needs more time in the oven. More variations, minigames, maybe a place where you can always sell, just for less.
Graphics wise the game is okay, lacks animations and probably some scene transitions could elevate it a bit more!
sfx and mx are missing completely. I can advise bfxr or similar tools, alternatively use audacitiy to do some sfx yourself and bitcrush them for the gameboy feel!
Good idea to build upon, well done!