Thanks for comments. This definitely still has a bug that can occasionally print a (magenta food) that doesn't count, and you can't progress. And it IS too hard - I've been playing it again today (on 200% speed on emulator it feels quite responsive), but I can't get close to my personal best. I think when making it I tweaked it to be as challenging as I could just-about not cope with, which is where I think arcade games should be. But at that point I'd been practicing, now - after not playing for a few days with dulled reflexes it's frustratingly difficult.
And thank you - the 'hunger' (and graphical representation of it) was the thing I was most proud of here. I don't *think* I've seen that in a snake game before.