Whurricane16 has ported SpaceJumper to the DC, here’s what he had to say about this release:

“Space Jumper by by Andr? Schnabel. This is a nice game for those who like overhead shooters. This needs a keyboard to play but I wouldn’t mind putting in the controller code if their are enough requests.“

The game can be downloaded from WH16’s site

Thanks to the emu news posting superstar known as Wraggster for the info.