That's probably becuase I never released the source for the HighScore and Score classes - it should still recognise them though, but they probably won't show up in the extra classes menu like you've realised. What problem is it that you're having? I'm not 100% sure if the classes I used in the highscore demo were actually the latest ones, but it's probably better to grab them from http://www.greenfoot.org/greenroom/scoring/test/ rather than the highscore demo and see.

Heya, The problem here is that you need to add objects within your code, because as you may have spotted we can't add them interactively later! For more details on how to do that, see here: http://www.greenfoot.org/greenroom/images/1/12/Adding_objects.pdf

They keep pushing me offf! In terms of the physics bugs though, as far as I can see they're all gone - guess there might be a couple still in there but I had a fair go over the ones that were there originally and they didn't seem to be there anymore (and alas I found playing it much harder without any cheats! :P)