For an unreleased prototype, Lord of the Rings is still a great great. The quest is simple, reach Rivendale. I've never successfully reached the Elvin City, and I'm not even sure it exists.
This is a great way to spend some time on an Atari Adventure. Read the books and play the game.
It seems that this would have been part 1 in a 3-6 part recreation of the Lord of the Rings. This could have been the original Bit Trip Runner-style game, stretching across genres. Still a great game, and a welcome addition to the very small adventure games 2600 library.