Released on; VIC-20 and Sinclair Spectrum in 1982.
Text taken from this page on the Llamasoft blog:
This was an “extended mix” [of Rox II] for the 8K Vic which added UDGs and slightly fancier presentation. Llamasoft never sold this version to my knowledge so I guess it was probably part of the same package [including Rox II] sold through DK’Tronics, as an optional version for people with the 8K Memory Expansion in their Vic.
VIC-20 Download
Spectrum Tape Download
Spectrum Z80 Download