Here is the full list of all 11 Desert Ashes achievements.
Destroy 4 units in one turn.
Destroy 3 units in one turn.
Destroy 5 units in one turn.
Complete the Winged Uprising episode.
Complete the Winged Assault episode.
Complete the Landian Strikeback episode.
Beat the AI in a skirmish match.
Played an online match.
Win an online match.
Win 5 online matches.
Level-Up in multiplayer stats.