Geometry Wave: Online Editor lets you play and create levels in a wave style game. I see the main goal is to complete levels, and the main mechanic is avoiding obstacles.
Use the W key to move, and avoid obstacles in the levels, and share your creations.
Controls are not stated, and you can create an unlimited number of levels and share them. The description mentions over 65 levels exist.
Focus on the mechanic of avoiding obstacles. Practice creating levels to improve your skills.
Q: What are the controls? A: The description does not state specific controls.
Q: What is the objective? A: The objective is to complete levels and create levels.
Q: What stated features exist? A: Over 65 levels and unlimited level creation are stated.
Q: What is the main mechanic? A: The main mechanic is avoiding obstacles.