Thank you for your extensive reply. This is really helpful. And thanks for all the kind words!
1. I know... I am from the prehistoric game era when games made you play for two hours, and when you made a crucial mistake, it was game over. Start all over... Since this game was inspired by those old games, I wanted it to feel a bit like that.
2. But giving power ups during the boss fight would be a good idea. Now it feels unfair sometimes.
3. Also very helpful. The thing is, sometimes as the programmer you forget that certain elements aren't obvious at all. Your suggestion makes sense.
4. I didn't know about the Firefox glitch. I don't know how to improve that, but I can provide downloadables for win / mac / linux.
5. Yeah, after I posted it, I realised the title was pretty dumb. It was my working title I suppose and never thought of a decent name. The third day was my son's birthday, and I couldn't spend more time on the game, so I decided to leave it.
Again, thanks very much!