Oh, you're supposed to press S or the down arrow on the door. You can get to three further levels. It's described in the About menu. I hope you're feeling confident enough soon to try again.
Thanks a lot! I've been nervous about this game's feedback ever since the voting started. Yeah, when I saw the theme I decided that I might as well count like Abraham Lincoln. And the "score" thing returns in a pretty major way by the time you get to read the credits.