I specifically mentioned that I am not the creator and that I do not know who the creator is. Like I said, I originally played this about year and half to two years back. At the time, there was no uploaded maps that I could locate. I have seen uploaded maps more recently, like the ones posted by Sgt. Johnson, since November. I cannot verify if he is or is not the original creator, and if he is, I am willing to comply with whatever he wishes.
As for design, I do not plan on changing or fixing the vulnerability when you switch. I like the fact that that are a few levels under have a chance to catch up. I specifically don't the basic footman/hero arena that whoever gets ahead, basically grows his lead and wins.
As for the upgrades, it's a work in progress. It will get better. I started off with a basic, 1 dmg, 5 range, 1 hp, 1% attack speed. I don't plan on ever making it very strong. Upgrades are going to be cheap and small, but they'll even out.