I could look into some ways to implement an upgrade tree into my current, non shared lore. I like that idea. I am also going to be looking into expanding the lore via an entrance cutscene and environmental effects. One of my main questions would be on difficulty scaling. I'm currently thinking about different ways to scale the difficulty. I think that just increasing the number of enemies per wave was not the best choice, but instead manipulate health and damage variables, and still have the amount of enemies as another way to increase the difficulty scale. Then also new spawner locations to pick from random areas, and expand the ways that enemies may spawn. Let me know if you have any thoughts on that.