The two versions of Zaxxon for A8 (16k and 32/48k A800 version)

I don't own either yet but when I do search for it I seem to only find the 16k version on tape or cart. Can anyone tell me what the differences are between the low and high memory versions are as screenshots via google image search don't look different?

Also is the 32/48k version available on tape or is it a disk only title?