2D graphic assets

In the following section, we will describe the most important types of 2D assets used in the game development.

Sprites

Sprites can be defined as game objects that have a role in the gameplay of a title: the main character (we use the word character here in its broadest meaning: a space ship is a character), enemies, bullets, and collectibles are all examples of sprites. Sprites are usually animated, which means that the artist draws a sequence of frames representing the key positions the game object assumes during the animation for each animated character and for each specific animation. The final result is an image called spritesheet that contains all the animations of a game character. The following figure represents part of the spritesheet of Super Mario Bros for the NES.

Once the sequences are made, it's up to the programmer to invoke the correct sequence for each desired animation through code. The 2D-oriented game engines, such as GameMaker (http://www.yoyogames.com...