This is one of the best Ultima's, and one of the most imaginative! Martian Dreams is an amazing RPG. The complete game is on auction here:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=8119564100&ssPageName=ADME:B:LC:US:1
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=8119564100&ssPageName=ADME:B:LC:US:1