Here is the full list of all 17 Sun Mystery - there are Playtest achievements.
Play 100 games
Play a card to cause 200 damage
Use the Nüwa character to win a game on Standard Mode Difficulty 10
Play a card to receive 200 armor
Use the Shennong character to win a game
Use the Shennong character to win a game on Standard Mode Difficulty 10
Win a game on Standard Mode Difficulty 5
Win a game on Standard Mode Difficulty 1
Use the Nüwa character to win a game
More than 20 cards in the deck and win the game
Win a game victory
Restore 50 health points in a battle
Unlock lv6 Sky Map Reward
After winning the game, have 1500 coins
Kill a boss within 3 rounds
Less than 6 cards in the deck and win the game
Play a game