Here is the full list of all 25 Kittens of Fear achievements.
Complete Classic Mode.
Complete Classic Mode with >25% loot average and <15 minutes.
Complete Classic Mode with >60% loot average.
Complete Classic Mode in under 7 minutes.
Complete Classic Mode with a score of 50,000 or higher.
Clear the Forest stage in Quick Play.
Clear the Study stage in Quick Play.
Clear the Kitchen stage in Quick Play.
Clear the Cave stage in Quick Play.
Clear the Basement stage in Quick Play.
Clear the Cultist Rooms stage in Quick Play.
Clear the Dev stage in Quick Play.
You DID finish the other five, right?
Clear the Cultist Rooms stage in Quick Play with 100% loot average.
Highlight a Shadow Cat with your Enchanted Flashlight.
Complete Classic Mode without using the Enchanted Flashlight.
Pet a Chaser cat.
Pet a Shadow cat.
Complete Fear Mode.
Complete Fear Mode with >25% loot average and <15 minutes.
Complete Fear Mode with >60% loot average.
Complete Fear Mode without using the Enchanted Flashlight.
Clear a Fear Mode stage that has a Threat Score at or above 100.
Complete Fear Mode with a score of 100,000 or higher.
Pilfer the Magic Urn loot item.