Geometry Wars in 25 lines of ActionScript source code

I recently noticed that Keith Peters' 25 lines competition and all the entries have been purged from the internet, so in case you missed it first time, here's my port of a Geometry Wars style game, with source code below. Click to view.

Here's the source, under free for commercial or non-commercial use MIT license. It gets cut off quite badly by blogger, so you're better off just clicking here to download. To run, just paste it into the timeline of CS4/CS5. I know that's a bad way to do things, but it was the rules of the original competition. If someone wants to make the necessary tweaks to compile it under the Flex compiler, I'd be very happy to post their code. Enjoy!

/**
* 25-Line ActionScript Contest Entry
*
* Project: Trigonometry Wars
* Author:  Iain Lobb - iainlobb@googlemail.com
* Date:    27 NOVEMBER 08
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/

// 3 free lines! Alter the parameters of the following lines or remove them.
// Do not substitute other code for the three lines in this section
[SWF(width=400, height=400, backgroundColor=0x000000, frameRate=24)]
stage.align = StageAlign.TOP_LEFT;
stage.scaleMode = StageScaleMode.NO_SCALE;

// INSTRUCTIONS: PLEASE NOTE IT CAN TAKE A WHILE BEFORE ENEMIES APPEAR SO PLEASE BE PATIENT!

// 25 lines begins here!

var enemies:Array = [];

function createOrUpdateEntity(props:Object, entity:MovieClip = null, updateFunction:Function = null, drawCommands:Vector.<int> = null, drawShapes:Vector.<Number> = null, colour:uint = 0x000000):void
{
if (!entity) entity = MovieClip(addChild(new MovieClip()));
if (colour) entity.graphics.lineStyle(1, colour, 1.0, false, "normal", null, null,3);
if (drawCommands) entity.graphics.drawPath(drawCommands, drawShapes, GraphicsPathWinding.NON_ZERO);
if (updateFunction != null) entity.addEventListener(Event.ENTER_FRAME, updateFunction);
for (var thing:String in props) entity[thing] = props[thing];
if (props.array) {props.array.push(entity)};
}

function updateShip(event:Event):void
{
createOrUpdateEntity({x:MovieClip(event.target).x + ((mouseX - MovieClip(event.target).x) / 5), y:MovieClip(event.target).y + ((mouseY - MovieClip(event.target).y) / 5),  rotation:(Math.atan2(mouseY - MovieClip(event.target).y, mouseX - MovieClip(event.target).x) * (180 / Math.PI)) + 90}, MovieClip(event.target));
createOrUpdateEntity({x:MovieClip(event.target).x, y:MovieClip(event.target).y, rotation:MovieClip(event.target).rotation, updateFunction:updateBullet, filters:[new GlowFilter(0xFFFF00)]}, null, updateBullet, Vector.<int>([1,2,2,2]), Vector.<Number>([0, 0, 3, 7, -3, 7, 0, 0]), 0xFFFF00);
if (Math.random() > 0.985) for (var i:int = 0; i < 20; i++) createOrUpdateEntity({x:300 + (Math.sin((i/20)*2*Math.PI) * 400), y:300 + (Math.cos((i/20)*2*Math.PI) * 400), rotation:0, array:enemies, updateFunction:updateEnemy, filters:[new GlowFilter(0xFF0000, 1, 12, 12, 4)]}, null, updateEnemy, Vector.<int>([1,2,2,2,2]), Vector.<Number>([0, 0, 10, 10, 0, 20, -10, 10, 0, 0]), 0xFF0000);
}

function updateBullet(event:Event):void
{
createOrUpdateEntity({x:MovieClip(event.target).x + (Math.cos((MovieClip(event.target).rotation - 90) * (Math.PI / 180)) * 12.5), y:MovieClip(event.target).y + (Math.sin((MovieClip(event.target).rotation - 90) * (Math.PI / 180)) * 12.5), rotation:MovieClip(event.target).rotation}, MovieClip(event.target));
if (MovieClip(event.target).x > 400 || MovieClip(event.target).x < 0 || MovieClip(event.target).y > 400 || MovieClip(event.target).y < 0) killEntity(MovieClip(event.target), false);
for (var i:int = 0; i < enemies.length; i++) if (Math.sqrt((((enemies[i].x - MovieClip(event.target).x))*((enemies[i].x - MovieClip(event.target).x))) + (((enemies[i].y - MovieClip(event.target).y))*((enemies[i].y - MovieClip(event.target).y)))) < 10 && this.contains(enemies[i])) killEntity(enemies[i], true);
}

function killEntity(entity:MovieClip, doExplosion:Boolean):void
{
if (this.contains(entity)) { removeChild(entity) };
entity.removeEventListener(Event.ENTER_FRAME, entity.updateFunction)
if (doExplosion) { for (var i:int = 0; i < 10; i++) createOrUpdateEntity({x:entity.x, y:entity.y, rotation:i * 36, updateFunction:updateSpark, filters:[new GlowFilter(0xFFFFFF)]}, null, updateSpark, Vector.<int>([1,2]), Vector.<Number>([0, 0, 0, -10]), 0xFFFFFF) };
}

function updateSpark(event:Event):void
{
createOrUpdateEntity({x:MovieClip(event.target).x + (Math.cos((MovieClip(event.target).rotation - 90) * (Math.PI / 180)) * 12.5), y:MovieClip(event.target).y + (Math.sin((MovieClip(event.target).rotation - 90) * (Math.PI / 180)) * 12.5), rotation:MovieClip(event.target).rotation}, MovieClip(event.target));
if (MovieClip(event.target).x > 400 || MovieClip(event.target).x < 0 || MovieClip(event.target).y > 400 || MovieClip(event.target).y < 0) killEntity(MovieClip(event.target), false);
}

function updateEnemy(event:Event):void {createOrUpdateEntity({x:MovieClip(event.target).x + ((mouseX - MovieClip(event.target).x) / 45), y:MovieClip(event.target).y + ((mouseY - MovieClip(event.target).y) / 45), rotation:0}, MovieClip(event.target))};

createOrUpdateEntity({x:300, y:300, rotation:0, filters:[new GlowFilter(0x00FF00)]}, null, updateShip, Vector.<int>([1,2,2,2,2, 2, 2, 2, 2, 2, 2]), Vector.<Number>([-7.3, -10.3, -5.5, -10.3, -7, -0.6, -0.5, 2.8, 6.2, -0.3, 4.5, -10.3, 6.3, -10.3, 11.1, 1.4, -0.2, 9.6, -11.9, 1.3, -7.3, -10.3]), 0x00FF00);


// 25 lines ends here!