Oh sorry to hear that. We wanted it to be hard in order to get the satisfaction of figuring it out, didn't think it might be too hard. In the page we've written some hints before giving the solutions, which are vague enough that they don't spoil anything and they give you a slight nudge towards playing the game right. Hope you could give it a try again in the future.
Yeah the problem with fullscreen in web is that the browser by default uses it to minimize fullscreen, so it doesn't work as expected in game. Best way around it is to rebind that key to "P" or something. If you're talking about the locked door code entry screen, pressing the interact button again while in that screen should close it.
Thanks for the kind words!