Here is the full list of all 16 MechoEcho achievements.
Complete Level 27 - "The Tower" without using Wheels
Complete 25 Levels.
Complete Level 20 - "Alone, but Able" without using Linear Engines.
Complete 20 Levels.
Complete Level 17 - "Spinning the Web" without using Motorized Joints.
Complete Level 15 - "Not Giving Up" without using Motorized Joints.
Complete 15 Levels.
Complete Level 13 - "Response to Peril" using only one Wheel.
Complete Level 10 - "Adapting to Scarcity" without using Linear Engines.
Complete 10 Levels.
Survive a close encounter with the Unlings.
Complete 5 Levels.
Complete 30 Levels.
Climb the tower in the Sandbox
Complete 5 levels from the first expansion.
Complete 10 levels from the first expansion.