gibdo 介绍
Gibdo 是一个至上而下的 2D 的 HTML5 Canvas 游戏引擎，采用
CoffeeScript 编写，主要特性包括：
- A scrolling view window that tracks the player across the game world.
- View limit detection to allow the player to move off the centre of the screen as edges are reached.
- Collision detection.
- Keyboard input.
- Sprite animation.
