Balancing the difficulty

I've uploaded a new version of Unbeatable Snake after some player feedback. It turns out, I didn't test the hard mode enough, and it's not just unbeatable but mostly unplayable. I also had some complaints about Normal being too hard. So, I decided to make Normal the new Hard, and make Normal halfway between that and Easy. That should make Hard very playable, Normal more reasonable for a wider audience, and Easy there for anyone who just wants to play casually.