This is far from my best work, doesn't even have a combat system, but I've scrapped/ran out of gas on a few huge projects at this point so I just wanted to get something out. Defenders is regressing back to what it was and it kind of hurts. Despite what I just said, I decided to set up a new system of enemy spawns for this project. Rather than passively spawning enemies or using hardcoded wave systems, this uses an algorithm to spawn waves that spawns more enemies the higher the wave number gets.
