Using a linked list in your game

Linked lists are awesome data structures that are particulary useful for JavaScript games. Unfortunately, there is no linked list data structure in JavaScript. Fortunately, it's easy to make one yourself (or you can just copy mine).

Flipping an image vertically or horizontally

This is a very useful piece of knowledge if you are making JavaScript games. This way, you won't have to make duplicate images.

Separating game logic with graphics

If you are unsure how to separate game logic with graphics, then this is a must for you. It also adresses how to ensure the game runs at a constant speed.

Animating images as effective and logical as possible

You could just use animated GIF files, but making your own animation system with PNG files does more than just make you smug and superior. It offers greater control and can be integrated into your separation of game logic and graphics in a very elegant way.

Allowing remapping of keys in JavaScript

You might at first think that you have picked the best set of controls for your users. But considure that not everybody uses an US keyboard, and somebody might want to play your game on something else than a computer, like the Wii.

Shifted Grid Collisions

If you have an action game with scrolling, you are bound to have run into this problem. There is simply too much resources spent on constantly checking if objects are colliding. Using shifted grid collisions, you can avoid this to a certain degree.

Adding sound effects and music

JavaScript has no support for sound effects or music (at least not cross browser), but due to the wonders of sneaky programming, it's now possible with using a small flash file. The only confort I can offer is that if the user doesn't have flash, all he will miss out on is the sound and music, the game will still play.