[m-photonic]

Apparently it's an Apple II game, not a CGA game. I was fooled too though.

[midas007]

Thanks. s/CGA/HGR{,2}/

Neat read (I never coded for Apple II):

https://en.wikipedia.org/wiki/Apple_II_graphics#High-Resolut...

[DerekL]

Actually, they did port it to IBM PC and TRS-80 Color Computer.