Creating a Vertical Shooter

Vertical shooters are also known as Fixed Shooter.

A fixed shooter has players only able to control their two-dimensional position on the screen and sometimes the direction they are facing*
 
*Wikipedia

So, we will create a game using our super hero Pawel to kill dragons that are coming from one side of the screen. I have provided an FLA with all of the graphics you will need, but you will need to place the graphics in the right spot. This tutorial is more of an explanation of the code with some design work as opposed to a fully-featured tutorial covering every aspect of a vertical shooter.

The following animation is an example of a vertical shooter. Click inside the animation to give it focus. Use your left and right keys to move left and right, and press the up key to fire an arrow at a dragon.

[ an example of a vertical shooter ]

Let's Start
Because there are some sprites in the game, I have provided them for you. That way, you can focus more on the Flash as opposed to the actual design work. Download and open the following FLA for the sprites:

Download Sprites FLA

Now that you have your list of sprites, let's continue. We need a sprite to make it walk, in this case I use a movieclip of Pawel (see sprite.fla) and as he is a knight, the instance name is knight:

On another layer, in the first frame of our timeline copy and paste the following ActionScript:

//---- variables ----

var steps:Number = 5;

var spriteX:Number = 265;

var spriteY:Number = 265;

//---- functions ----

function checkKeys() {

if (Key.isDown(Key.RIGHT)) {

spriteX += steps;

} else if (Key.isDown(Key.LEFT)) {

spriteX -= steps;

}

}

function updatePawel() {

knight._x = spriteX;

knight._y = spriteY;

}

this.onEnterFrame = function() {

checkKeys();

updatePawel();

};

Ok, our hero is moving from side to side on the screen but, he can even move outside of the stage! We can animate the legs and the arms so it will look better and it will add the option of throwing arrows (we don't have arrows yet).

If you double click on your knight movie clip, you should be in the timeline for that movie clip. You will see three layers corresponding to the body, arms, and legs:

More importantly, notice that the arms and legs are movie clips with the instance names...arms and legs! If you look inside the arms and legs movie clips, you will find that they have some keyframes that provide some extra animation for movement.

Let's modify our code to take advantage of the new movement in the legs and arms:

//---- variables ----

var steps:Number = 5;

var spriteX:Number = 265;

var spriteY:Number = 265;

//---- functions ----

function checkKeys() {

if (Key.isDown(Key.RIGHT) && spriteX<510) {

spriteX -= steps;

knight.legs.play();

} else if (Key.isDown(Key.LEFT) && spriteX>40) {

spriteX -= steps;

knight.legs.play();

}

if (Key.isDown(Key.UP)) {

knight.arms.play();

}

}

function updatePawel() {

knight._x = spriteX;

knight._y = spriteY;

}

this.onEnterFrame = function() {

checkKeys();

updatePawel();

};

In the next page, I will explain the above code and guide you through adding features such as the background and arrows.

Onwards to the next page!

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