In that era, I had first seen a 2D 'computer maze' game on teletype (i.e. paper) terminals of the student friends I knew, who were learning mainframe things at home in a period (70's/80's) before computing got personal.

We kids weren't allowed to play that game much (better, Chess), since it emitted reams and reams of updates, but there was always about a 60cm pile of green teletype paper around, for re-using with a different colour ink ribbon ..

Seeing it on a ZX81 in this manner is just glorious!

And now, watching my kids playing Counter Strike in the background while I hack on some playDate thing or two .. what a change in resolution.