Using the Quintus Engine with TypeScript. This is just a proof-of-concept, it's WAY too early to actually use.

app.ts.js

/// <reference path="quintus.d.ts" />

var Q = Quintus()
        .include("Sprites, Scenes, Input");

// No need to call Q.Sprite.extend
class Player extends Q.Sprite {
    init(p) {
        super.init(p, {
            asset: "somegraphic.png",
            x: 320/2,
            y: 420/2
        });
    }
}

Q.scene("level1", (stage) => {
    stage.insert(new Player());
});

window.onload = () => {
    Q.setup();

    Q.load(["somegraphic.png"], () => {
        Q.stageScene("level1");
    });
};

quintus.d.ts.js

module Q {

    function include(plugins: string): Q;
    function setup(): Q;

    function scene(levelName: string, stageFunc: (stage: Stage) => void );

    function stageScene(sceneName: string);

    function load(fileNames: string[], callback: Function);

    class Sprite {
        init(p: any, options: SpriteOptions) : void;
    }

    interface SpriteOptions {
        asset?: string;
        x?: number;
        y?: number;
    }

    interface Stage {
        insert(object:Sprite): void;
    }
}

var Quintus: (options?: Object) => Q;