Genuinely loving this, what a fantastic achievement!
I think I might have seen a little bug that you might want to take a look at? Sometimes (maybe always, I'm not sure) when I start a level with a new weapon on it, my weapon indicator in the top-right shows the new weapon's name even before I've found and collected it.
Congratulations, I'm very much looking forward to seeing any further tweaks or enhancements you make!