UPDATE 24 FEB 2020:
I'm back to my normal job which means I'll have less time for working on this game . . . but I am determined to keep working on it and get it done.
Thanks to everyone so far for viewing and downloading it. I've already heard feedback that the screen size is a bit too big and the second weapon will not fire if you have the Caps-Lock key on (my 7-yr old discovered that one!).
So I've added those two things to my "To Do"s.
The awesome people at the QB64 forums have given awesome pointers on how to fix the firing logic so that I can have one shot fire with each press of the spacebar, just like in a normal top-down shooter. I've been working on that this afternoon. Once I get it to work I'll be able to implement it in the game and add better weapons, which I'm really excited about!