I don't think we should have to worry; mainly because we don't plan on selling the game, but also because the game isn't based solely on the original work, and because the trademark has been cancelled/abandoned.
Yeah, i think we have alot more creative freedom just because we are a fangame and are not charging anyone for anything. I mean we are blatently using space quest. I wouldnt worry about it. Unless the makers of the xaxxon game come after us just leave it. On the extreme outside change they do then we change her last name.