1978 · Adventure · DOS · Amstrad CPC · ZX Spectrum · BBC Microcomputer System · Call-A-Computer time-shared mainframe computer system · Acorn Archimedes · Amstrad PCW
Achteon was originally released on a mainframe computer, similar to Zork. And just like Zork it is a fantasy treasure hunt with 400 rooms and 200 objects, and therefore is much bigger than its more famous companion.