Flyte is a game engine that makes it easy to create scrolling games within the Flash IDE or with Flex. It was designed with ease of use in mind, which means an emphasis on minimizing the code you have to type and finding creative ways to the Flash workspace.

Some features:

• Pixel-perfect bitmap-based collision detection;
• Game initialization, event handling, and level management;
• Level elements like barriers, ladders, switches, and platforms;
• Tweening game elements without animation or code;
• Game element animation;
• Character-based gameplay and keyboard input;
• Enemies and AI;
• Checkpoints, goals, and hazards;
• Collectibles (health, coins, and powerups);
• Projectiles like bullets and grenades;

Sample

import org.flyte.events.GameEvent;

addEventListener(GameEvent.GAME_INIT,onInitGame);

function onInitGame(e:GameEvent):void {
    loadWorld(new ScrollWorld());
}