You actually did what was intended! The goal of the game is to overwhelm the hero. I think you either got lucky or are just that good at the game (maybe good at understanding the game) since most other people struggle even with the energy leech mechanic. I tried to balance the Trappers by making them exclusively for energy. You can spam them but it won't deal much damage and you usually won't get enough energy to spawn any other enemies. At least that was what i intended.
Thank you for playing the game!