Thanks norecess, that's great.
I do like programming the Plus, but am at the stage where I am working out how everything is done rather than coming up with something original. So, for example, I get fast sprites working but more as a proof of concept than anything good for a demo - but it does mean I have started a library of routines (and more importantly, understand how they work) which is useful when programming as you think to yourself "I have done this before, how did I do it" when you get stuck
I am hoping to release just a little demo soon and then work on putting something together more challenging in the new year.