Here is the full list of all 23 Merlin Adventurer Store achievements.
Entered the game for the first time.
Get 800 prestige points
Get 800 points style points
Earn 1,000,000 golds
Earn 10,000,000 golds
Reach NG+
Reach NG++
Reach NG+++
Reach the true ending
Meet all 24 characters
Sell 1000 goods.
Unlock all the dialogues of the Sister
Unlock all the dialogues of the Courier
Win the first place in the normal end
WuJie reaches lv.100
Flamingo reaches lv.100
Kim reaches lv.100
Jackson reaches lv.100
Tanuki reaches lv.100
Martin reacheslv.100
Unlock the 2nd dungeon.
Unlock the 10th dungeon.
Unlock all blocks of your decoration area.