The game is great and concept wise is amazing. Here's what Id say could make this game worth a Heck ton of money tho:
1. Maybe make the basement and upstairs as seperate levels, you could make it basically a campaign! Now sure you could do something crazy like make EVERY level a, well, Level. But this seems a lot better. (Plus the peach jumpscare at the end could be a way to transition to The basement ya?)
2. For harder difficulty's, you could make it to where the toads (I wouldn't recommend peach, but maybe for like Mini mushroom) Will check the chests if they haven't heard or seen Mario in a while. Making it to where you can't just hide in them forever.
3. Honestly, Make the outside playable again! It was so cool running outside and while I still have that version and what not It'd be cool if you could run outside again, at the very least I'd say going out the back door.
No I will say, I play on mac. So maybe the version Mac is on Simply doesn't have the features I remember, and thats A-OK! Just let me know! But still, Awesome Game. 10/10 would recommend.