Posted: Jan 09, 2014 Two trains battle for supremacy by rotating their cars' abilities on a deadly wheel of death.

Fig 174.1 - Choo-Choo, Mother F****r.

This is a competitive battle game between a number of different trains. At it's base level, each player drives a train around a semi-large open world, delivering supplies and passengers from one station to another. Use the money from making deliveries to upgrade your trains to include more and different types of cars, both to deliver more goods and to upgrade combat abilities of your train (adding armor plating or a cow catcher).

Weapons on the trains are automatic, based on firing arcs. The trains will automatically attack each other if they get near enough, and of course they can ram each other (possibly decoupling cars, which can then be stolen). When a train is defeated, it will soon respawn back at its home without any cargo.

Trains are controlled via a stylus interface, like a control panel, where you can not only manipulate how fast the train is going and where it will turn, but also manipulate the supplies inside the cars and rotate the battle rings.

Fig 174.2 - Better put a ring on it..

At the heart of the combat system is what I call the battle ring. It is a single ring with equipment slots that can be rotated clockwise or counter clockwise. This will affect which equipment slots are inside the car and which are outside, as well as affecting the firing arc of the weapons. The above illustration represents a single train car with a two battle rings, one for each side of the car. They each can be rotated independently of each other.

Equipment does different things depending on whether it is exterior or interior on the battle ring. The square equipment blocks are passive abilities, while the circles are weapons (and their associated firing arcs). A gun, for example, would fire when it is exterior and reload itself when it is brought inside. Passive buffs give the train car special abilities when inside and simply act as bullet sponges outside.

Fig 174.3 - Stoppers in action.

The battle ring does not rotate one slot at a time. Instead it is up to the player to put stoppers into the battle ring, between equipment slots. Then when the ring rotates, it will continue to do so until it hits a stopper. This allows the player to build a positional loadout. For instance, he could have a ring broken into two segments, allowing him to alternate them between inside and outside. Or he could put stoppers between several equipment slots in order to more finely tune the weapon firing arcs.

Fig 174.4 - Supplies!

The basic gameplay consists of going to a station that has goods for you to pick up. You simply stop the train at a station (hoping your enemy isn't nearby) and drag and drop the supplies into your train cars. Each train car can hold a number of supplies, but can be upgraded to hold more supplies, or even changed into a special type of car that deals with a particular type of supply better (you need to cattle car to carry livestock, tanker cars can't carry anything but liquids, refrigerated cars keep perishable goods longer).

Fig 174.5 - The people here are very thirsty.

There are various good producers around the map. A lumberyard may produce wood, for example. And there are stations that will announce their need for certain goods. One station may announce that it needs a certain number of a particular good. For each required good delivered, the player will make some money.

Fig 174.7 - This station demands men's restrooms.

Passengers work in a slightly different manner - more like Crazy Taxi. Pick them up in a passenger car, and they will have a destination they want to go and a time limit for delivering them (don't worry, it'll be a long limit). Their icon will appear on the map at the location you need to drop them off, turning gradually redder and redder as the time limit counts down. Stopping at a station will automatically cause passengers going there to disembark and the pay the player.

V.I.P.s are special passengers that imbue the player's train with special abilities as long as they are on board. For instance, they may cause the train to move slightly faster, or take slightly less damage. They also have no time limit, though if the player stops at their station, they'll disembark.

Though not illustrated above, there are special colored tracks that only specific player trains can travel on. These are largely used to protect the player's home base (where he spawns and buys upgrades) from other players, be it can also be used for player specific shortcuts.

- This idea was written down in my "dream journal" as "Circle Tanks". The battle ring concept was there, complete with passive nodes, stoppers, and that whole bunch of malarky. However, you controlled a tank instead. I realized that the complexity of rotating the battle rings in addition to controlling the tanks would've been too much for most mortal men to handle, and thought that the idea would work better with something on a more controlled path. Once I thought of trains, I realized that I could have multiple cars worth of battle rings, making the idea that much cooler!

- But how to control it? I was originally thinking keyboard controls - one button to rotate the left ring and one button to rotate the right. So each car had two buttons, and the engine had two buttons to switch tracks, which was unwieldy, to say the least. I decided to limit it to only one engine and three cars, but that's still 8 buttons. It was when I was deciding whether or not to add acceleration buttons to the engine that I remembered how The Legend of Zelda: Spirit Tracks used the touch screen as a control panel (and to a greater extent, Steel Diver). Realized immediately that a touch screen would make the complex controls much more manageable (and allow for both clockwise and counter-clockwise rotation!)

- I toyed with the idea of weight being important, such that an unbalanced train could skip the tracks if taking a turn too quickly. You'd have to rotate your battle wheels to manipulate your heavy equipment before taking turns. That seemed a little too micro-managing though.