Here is the full list of all 33 Miden Tower achievements.
Watched the opening.
First character joined the party.
All characters joined the party.
Took the upper tower back.
Confronted Rianne.
A sudden goodbye with Catherine...
Formed an alliance with the Resistance.
Brought peace to Neena.
Obtained the normal ending.
Obtained the true ending.
Walked 50,000 steps.
Walked 250,000 steps.
Walked 500,000 steps.
Collected 50 treasure chests.
Collected 100 treasure chests.
Collected 200 treasure chests.
Reached 30 combos.
Reached 100 combos.
Reached 200 combos.
Dealt 5,000 max damage to enemies.
Dealt 10,000 max damage to enemies.
Dealt 30,000 max damage to enemies.
Defeated 100 enemies.
Defeated 500 enemies.
Defeated 1,500 enemies.
Obtained 50 items with the magic cauldron.
Obtained 100 items with the magic cauldron.
Obtained 200 items with the magic cauldron.
Cleared all subquests.
Cleared the Bronze Cup.
Cleared the Silver Cup.
Cleared the Gold Cup.
Cleared the Bear Cup.