Here is the full list of all 13 Sons of Ra achievements.
Playing as Anubis, create 30 Mummies in one game (Online, or against a Hard AI)
Playing as Sekhmet, advance 20 units to maximum Battle Hardened rank in one game (Online, or against a Hard AI)
Playing as Ra, defeat 30 enemy units with Solar Flare in one game (Online, or against a Hard AI)
Playing as Set, have an opponent's own unit deal the finishing blow to their keep (Online, or against a Hard AI)
Playing as Isis, have 15 units gain the maximum number of Block stacks during one game (Online, or against a Hard AI)
Complete Arcade Mode as Anubis
Complete Arcade Mode as Isis
Complete Arcade Mode as Ra
Complete Arcade Mode as Sekhmet
Complete Arcade Mode as Set
Complete Arcade Mode without losing a single life
In an Online game, construct 2 Expansions, and unlock every Tower and Unit
Win an Online game in Sudden Death