^Sorry. I didn't realize you posted this. I posted a new version, and noticed it as I was going to announce a new version being uploaded. Needless to say, I haven't addressed those concerns, but I will write those down and work on them.
I think the game modes were implemented at that point. I designed the button to be clicked and the current option being shown. I don't like the current setup, but it was meant as a temporary solution (because editing a text file would be even worse). I think having the options on a separate screen would be a good idea. I had it so pressing escape exits the game, but dropping out to the main menu would be better. And I don't think it will be that hard to implement. A menu would be a good idea too. I put the High Score board on the Game Over screen, but pressing a key could go to a menu instead of relying on key inputs. I wasn't going to implement firing during reloading, but having multiple guns and switching if necessary makes it easier to manage enemy waves.
Regarding the new release: I uploaded it from a different computer than my testing unit, and the health bar wasn't visible on this one. I'm not sure why it isn't showing up, but I will have to look into it.