Here is the full list of all 21 Insignificant achievements.
Cursed to spend the rest of your days insignificant and alone.
Fire far too many spells from your fingertips.
Find all 13 audio logs before beating the game.
See one of the endings to the game.
Complete the game in New Game Plus mode.
Obtain a Tama Buddy of the highest rarity.
Use Cagetama for the first time.
Collect every Tama Buddy in the game.
ACH_DESC_OBTAIN_FORBIDDEN_MANCY_NOT_PLAYER_ACCESSIBLE
Unlock and fully upgrade all Mancy powers.
Learn all crafting recipes.
Use Enchtantment to upgrade an item to Unique rarity.
Reach level 21.
Add all entries on Enemies to your Compendium.
Add all Tales to your Compendium.
Complete the Compendium by filling out each section of the Codex.
Encounter an important person in the underground river.
Defeat the boss in the basement of the office building.
Encounter an important person under the lake.
Defeat the boss locked away in the rural house.
Encounter an important person under Onion Mountain.