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