Here is the full list of all 16 Artificial Defense achievements.
Complete the Conquer Tutorial
Complete the Defense Tutorial
Complete the Offense Tutorial
Complete at least 4 challenges
Complete at least 8 challenges
Complete at least 12 challenges
Complete at least 16 challenges
Complete at least 20 challenges
Complete at least 24 challenges
Complete at least 28 challenges
Complete at least 32 challenges
Complete at least 36 challenges
Complete at least 40 challenges
Complete at least 44 challenges
Complete at least 48 challenges
Complete all challenges