is easier to teach OOP by using game design, because
in a computer game, everything is an object: the monsters,
wall segments, coins, bonuses, power-ups, and the guns and
bullets. Thinking about creating games means thinking about
objects and how they react to one another and to the player's
input. So the game creator naturally thinks in an object
oriented way. Overmars used GameMaker to create a game
[5], as Figure 1 shows. The designer creates objects. Some
objects have a visual representation, such as an animated
sprite. Others, like those that control game flow or maintain
the score, might lack this feature. Multiple instances of the
same object can appear in the game at the same moment.
Instances have properties. Some are built-in, like the speed
with which the instance moves and the sprite used to
represent it. Others can be defmed, manipulated, and
checked using actions or code. The user must defme each
object's behavior. While some objects, like wall segments,
will have no behavior, others, like the avatar representing the
will most like have com icated behavior.