Thanks, I'm really glad it runs smooth. Open-source and modding would be fun, but I'm a little shy about sharing my source code. It's kinda messy.
I set the default assignments to what I think people should learn in order to have the most fun: all the gun keys adjacent to the WASD keys. But yeah, it's opinion. That's why configurable controls is the most essential feature for PC games.
I would like to make multiplayer mode in the future, and I have experience making p2p apps, so it can be done. It will not be pvp gameplay though; it will be players vs potatoes. I don't like pvp in online games, in principle.