http://www.proggies.uk/progs/zip/xmas2019.zip (101 Kb)
Needs a fast PC - it's written in BASIC, and there's rather a lot going on!
EDIT: Here's a very glitchy YouTube video (30 fps, 80% quality) of the demo in case anyone has trouble running the EXE:
https://youtu.be/tXLU-rvKDcg
This is almost certainly my last post here until at least 2021 because I'm dedicating 2020 exclusively to RISC OS-related things (have had several projects on the back burner for years).
Merry Christmas & Happy New Year to y'all...

David.
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