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Game Maker Tutorial

Creating Platform Games
Written by Mark Overmars Copyright © 2007-2009 YoYo Games Ltd Last changed: December 23, 2009
Uses: Game Maker 8.0, Lite or Pro Edition, Advanced Mode

Level: Intermediate Platform games are very common, in particular on handheld devices. In a platform game you look at the scene from the side. The player normally controls a character that walksaround in the world. This world consists of platforms. The player can walk on these platforms, jump or drop from one platform to the other, use ladders or ropes to get to different places, etc. On the platforms there are objects to collect, enemies to avoid or kill (often either by shooting them or by jumping on top of them), switches that can be pressed to open passages, etc. Also the playernormally requires skill to jump over dangerous areas. In some platform games you see the whole level at once, but in most you see only a part around the character. In such a case, finding your way around becomes an additional challenge. Creating a good platform game is not trivial, also not with Game Maker. There are three important aspects to take into account:    Creating natural motion for thecharacter. Creating enough variation in monsters, background, etc. Carefully designing the levels such that they are fun to play and get increasingly difficult.

In this tutorial you will learn how to make a simple platform game in Game Maker. We will build the game in a number of steps. The various steps are available as editable games in the folder Examples. They consist of just one level todemonstrate some particular aspect. You can use them as a basis for your own platform games.

The Basics
We start with the most simple platform game. You can find it in the file platform_1.gm6. In each platform game there are two basic objects: the character that is controlled by the player, and a block object that is used for the floors (platforms) the player can walk on. The same block is oftenused for the walls that the player cannot pass. We need two sprites: one for the character and one for the block. For the character we use a simple ball. For the block we use a black square. We create two objects. The block object is simply a solid object that has no events or actions. It simply sits there. The character object is a lot more complicated. 1

Motion The crucial aspect we treat inthis first section is how to define the motion of the character. The problem is that the character must walk on top of the floors. It must not intersect the floor. If the character jumps or falls off a platform it must land correctly on the next platform. There are a number of different ways in which the character can walk, jump, and fall. Different platform games use different modes. Normally wejust use three keys to control the motion. The left arrow key should move the character to the left, the right arrow key should move it to the right, and the up key or the space key makes it jump. Let us first consider the left and right motion. The first choice to make it whether the player can only change its direction of motion while on a platform or also in the air while jumping or falling.Even though the second option is not natural (it is rather difficult to start moving left while you are falling down) we decide to go for the first option, that is, we allow horizontal motion wherever the character is. This tends to lead to nicer game play and is actually also easier to implement. The second choice is whether the motion has constant speed or whether it accelerates when you keep thekey pressed. For simplicity reasons we opt for the first choice. Allowing for acceleration though normally gives nicer game play: the player must for example start a run at a distance to jump over a wide hole. As you should know there are different ways to let a character move. We can set a speed of motion or we can simply move the character directly. In platform games it is normally the...