Not many have heard of it probably, but:
Newcomer.
It was developed by a Hungarian team, but as far as I know there is an English version. It's an RPG in which you move around like in Doom (but you can only turn 90 degrees). Due to the limitations of the C64, you can only see your enemies as splash art before the fight (which is character based), and it involves a lot of disk swapping (it came out on a whopping FIVE floppies!). But it's a huge game: countless characters, conversations, fights, items to run into, and you can proceed by talking to the right people, using the right items, mentioning the right topics (sometimes you can type in key words).