Based off the 1981 Konami coin-op of the same name, Locomotion is really an update of the old sliding tile puzzle but with a twist. Not only do you have to slide the various track pieces around to keep the train from running off the track (no Amtrak jokes please), but you also have to go through all the stations to pick up passengers before they riot. With a strict timer and tricky mazes, this simple task isn't nearly as easy as it sounds. Oh did I forget to mention the runaway crazy trains?
The Locomotion board is made up eight tiles, each with a different section of track. Your goal is to arrange the tiles so that your train stays on track and pick up all the passengers in the stations. While this task wouldn't be too difficult if you had all the time in the world, in Locomotion you only have a short amount of time before the passengers start trouble. A few seconds before the timer is about to reach zero a station will begin to flash and a warning alarm will sound. This is your cue to "Make Trax" to that station ASAP! If the timer reaches zero before you reach the station, one of two things can happen. Either the passengers will blow up the station in a riot, or they will construct a crazy train to get you. I guess these guys mean business!
If a station is blown up in a riot you will lose the "Prefect Clear" bonus, but suffer no other ill-effects (although you will not be able to pass through that station again). However if the passengers construct a crazy train, another train will be set on the tracks under the control of the computer. These crazy trains can really cause problems, so try and trap them on an unused section of track. If during the course of the game you get caught in a loop (circling the same section of tracks over and over again), a warning klaxon will sound. This is your cue to get a move on and change course. If you ignore the warning the passengers will construct a loop sweeper to come get you. The loop sweeper appears as a star and will travel down the tracks at lightning speed, so try not to let this happen.
Although finding a path through the maze of tracks may sound tricky at first, it's really not all that bad. The 2600 version of Loco-Motion features a "path finding" system of sorts which makes a tough task much easier. As you chug along down the tracks, your train will "shoot" out a little square which will travel down your current path until it reaches a dead end. By watching where this square goes, you can easily plan your path in advance. However watch out for "Train Stops" which appear as barriers across the track. These stops will blow up your train if you hit them
After getting beaten to the punch on the Intellivision by Activision's Happy Trails (a similarly themed game starring a cowboy), Mattel decided that they would make a 2600 version of Locomotion While the Intellivision had no problems drawing the curved diagonal tracks of the original arcade game, the 2600 wasn't quite up to the task. Unfortunately the 2600 version looks rather blocky compared to its Intellivision counterpart due to the use of playfield graphics to draw the tacks. The 2600 version also seems to be void of any addition eye candy such as the smiley-faced passengers and station lights. Thankfully the 2600 version of Locomotion plays really well, and that's the most important thing.
Although Locomotion was finished and in the quality assurance process, it was canceled for unknown reasons. Strangely, even though Mattel owned the console rights to Locomotion, Atari planned a version for the 5200 and even produced a prototype box! Is it possible that Mattel licensed the 2600 and 5200 system rights to Atari? A mockup screenshot exists which shows very different graphics.