Merlin's Walls is the first 2600 game written by Igor Barzilai, but it actually started as a challenge - can you program the 2600 to do true 3-D?  Not "cheated" 3-D like Tunnel Runner and Escape from the Mindmaster, but real 3-D, where the world as drawn from the viewpoint of the character, and the player is not restricted to just turning 90 degrees left or right.

It turns out it can be done, though the way the 2600 draws a screen forced Igor to draw the screens from left-to-right as if from up-to-down, meaning you need to turn your TV on its left side to view it comfortably.

As far as the game itself, the idea is that you have to escape 16 mazes that Merlin has constructed for you.  There are some walls that are special: some give you more time, some give you explosives that you can use to blow up a normal wall segment with, some are just landmarks (and can not be blown up), there is one exit wall, and there are other special walls on later levels.

You don't have a lot of time to get out of the maze, so it becomes important to know where you're going.  A map of the first maze is provided in the instruction booklet, but after that, you're on your own.  And time goes by so fast, it'll be hard to map each level (Ed.: Scott Stilphen created maps for all the mazes, as well as a complete video of the game).

The game has one serious downfall: the 3-D effect, no matter how cool it is that it could be done at all, is the game's biggest weakness.  Because you're not restricted to 90 degree angles, it's quite easy to lose your orientation.  You'll bump into walls (causing you to lose time) you thought you could pass safely, and you'll miss doorways you should have seen.  And there are some slight drawing effects that sometimes make the point where two walls meet look like a doorway when there isn't.  What's worse, the loss of orientation makes it hard to map levels, and if you don't map, you're forced to wander and remember, which is quite a difficult task.

You'll find that you have to randomly try the explosive on different walls and hope you find one that lets you into the rest of the maze, forcing you to potentially replay a level many times until you get it right.  It would be nice if the special walls occasionally came back to give you more time, or another shot at blowing up a wall, but that doesn't appear to be the case.

If you're into action games, Merlin's Walls probably isn't going to be a lot of fun for you.  If you like puzzle and adventure games, then this will probably be a little more fun, making maps and plotting your course through the mazes to make it through all 17 levels.  But in general, this is more interesting as an example of what can be done on the 2600 than as a game.