Here is the full list of all 13 ECON - there are Elemental Connection achievements.
Beat the Creative AI
Beat the Simplistic AI
Beat the Normal AI
Beat the Mindful AI
Beat the Thoughtful AI
Beat the Efficient AI
Lose against a human opponent
Win against a human opponent
Clear 10 Challenges
Clear all Challenges
Win a game without any misconnections
Gain 20 points in a single placement
Finish any competition with no mistakes by either player