I really enjoyed this prequel. I loved "Trick & Treat" when I played it, so this was quite the treat (no pun intended).
Also, while there are still achievements and a bad end I need to get, I've managed to get some of the achievements and the bad ends 1-5, so I thought I'd share how I got them here, seeing as how it's relatively simple to get the normal and true endings, as well as the achievements tied to them:
Bad Ends:
Bad End 1: Run into the candelabrum at the bottom of the kitchen approximately 5 times.
Bad End 2: Repeatedly taste the mixture in the cauldron. Taste it 2 times before stirring the cauldron or 3 times after stirring it.
Bad End 3: Eat from the bread in the top left of the kitchen or from the bowl of sweets on the dining table.
Bad End 4: Stir the cauldron approximately 4 times.
Bad End 5: Talk to all of the pumpkins in the pantry and garden, and then, sit down next to one of them.
Bad End 6: Right at the beginning of the game, repeatedly run into the door to the south until Charlotte comes home.
Missable Achievements:
Potion Master: Stir the cauldron perfectly the first time.
Potato Master: Peel the potatoes perfectly the first time.
Break Mugs: Break both the glass mugs.
Pumpkin Friends: Talk to all of the pumpkins in the pantry and garden.
Potato Harvest: Harvest all the potatoes in the garden.
Pumpkin Outfit: Put on the pumpkin outfit in the pantry.
Pink Outfit: Put on the pink outfit in the bedroom.
Please add on what I've missed to this list, and thank you for reading!