Here is the full list of all 26 Don't open the doors! achievements.
Bring the megabomb.
Find a book.
Kill 50 bees.
Kill 1000 bugs.
Kill 5 enemies with a single hammer srike.
Defeat the Arik.
Break the beetlejuice cauldron.
Defeat the Great Cactus.
Squash 100 chests.
Carry a large amount of money.
Drink 200 pots of compote.
Upgrade diamond armor to max.
Read all the diary parts.
Beat all the doors.
Kill 1000 flies.
Find all the gold keys.
Kill 10 enemies with a single hammer srike.
Kill 20 enemies with a single hammer srike.
Explode the main door.
Squash 2000 objects.
Defeat the Pumpkinello.
Wear the glasses.
Collect bee glue.
Don't take any reward from Mr. Bee and pass through the hive gates.
Die 25 times.
Kill 50 spiders.