Since drones and lurkers tend to go left and then down depending on where the player is, you can use that to make them decide to crash into the wall. If that doesn’t make sense, I can upload a vid to YouTube. I’m pretty surprised this glitch isn’t intentional! It seemed like a pretty cool Easter egg and a strategy that is hard to implement but still possible to use. I assumed that if it weren’t intentional, the enemies would just go out of bounds...
Also, the activation window for bullets might be a bit too large for your liking, since I have used it more than once to plow through large hordes of enemies without taking damage. If I were you, I would make it so that if the bullet is overlapping with an enemy or the bullets mother enemy, then it does not deal damage. For the most case, however, the way you programmed the game makes bullets entirely predictable. The only exception is when I get surprised by my own decoy and accidentally move into the bullets...