Here is the full list of all 24 Soda Dungeon achievements. It takes around 60-80 hours to unlock all of the achievements on Windows.
Complete 100% of the bestiary.
Win a battle by only defending.
Complete 50 levels with only one Soda Junkie.
Complete dungeon level 1000.
Complete dungeon level 750.
Steal essence from an enemy.
Reflect 100 damage from a single attack.
Find a legendary item.
Complete dungeon level 500.
Hope you're hungry.
Complete dungeon level 250.
Purchase all basic sodas.
Have one Knight defend for another Knight.
Find a rare item.
Inflict burn, sleep, poison, and confusion on one enemy.
Complete 100 levels in one trip.
Complete dungeon level 100.
Sell 100 items.
Complete 50% of the bestiary.
Slay 500 enemies.
Slay 10 bosses.
Enter a battle in the Arena.
Discover and explore an alternate path in the dungeon.
Complete your first dungeon trip.