It is very hard to describe the genius that is Loco-Motion, a simple puzzle game with complexities and fun that belie the first impression it makes. My description aside, you're going to have to play it for a few minutes to see for yourself.
Loco-Motion is like the puzzle you had as a kid that was a square of tiles with exactly one tile missing. You move the tiles into the missing slot (over and over again) to rearrange them to complete a picture correctly. LM plays just like that except it is a train on tracks that is going to stations all around the edge of the playfield. There is one open square and you have to use the joystick to move the squares around to maneuver the ever-moving train through all the stations on any level (you pick up passengers and score points at each station).
The problem is that all the tiles have different pieces and shapes of track on them and you have to line them all up correctly to get the train where it needs to go. To help you out, the game highlights brightly the current lined-up route you are on. Move a tile and change the route and the highlight changes accordingly. You die if your train runs off the track into the blank square, a dead end (there are many) or into another train.
Yes, there are other trains on the tracks and it's an important part of what you need to watch out for when you are doing your rearranging. The other trains usually aren't there to start a level, but are launched after a countdown. As I mentioned before, your goal is to get to each station and pick up the passengers there - if you take too long, the stations begin a countdown (it counts down the points the station is worth). If the countdown gets to zero, a train is launched and on the hunt for you.
Another feature is the throttle button. Push the button (the only one in use in this game) and your train speeds up. It's a cool little effect as it takes a moment to build momentum and also to slow down once you let go of the button. Speed helps you outrun other trains, avoid collisions at intersections, get to stations before the countdown ends, etc.
You'll get the hang of it quickly, but like all great puzzle games, the brilliance is in the complexity of the gazillions of options and things that can happen. Each time you move a tile, it's amazing how many things change. Like chess, the more moves ahead you can see, the better off you are going to be. Cool things happen under duress including moving the tile the train is actually on before it gets to the edge and plunges to its doom. The satisfaction of sliding the train into a new slot or changing tiles to keep the train going RIGHT BEFORE it's going to crash is awesome. Play the game for a few minutes - because at first it just seems slow and easy. And keep in mind, like most games, subsequent levels get harder and more demanding as you proceed successfully.
Loco-Motion is brilliantly simple and endlessly complex. You have to play it for a few minutes to start to experience the satisfaction of completion and pulling your ass out of the fire.
Bonus music trivia - The song Loco-Motion was a chart hit 3 times... 1963 by Little Eva, 1975 by Grand Funk Railroad and 1988 by Kylie Minogue. One of these versions was a favorite song of mine when I was in sixth grade, I'll let you figure out which.