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