GameMaker 2

First of all, use the most recent version of GameMaker, that is, use version 8.1. That makes it the
easiest for us to port the game to iOS (the operating system of iPhone, iPad, and iPod Touch) and
Android. You should develop your game on a PC. Because the PC is rather different from the iPhone
this might make it somewhat difficult to establish whether your game will work well on those
devices. We do not yet offer software to create builds for the devices yourself. Only when your game
is close to being finished and we are convinced we indeed want to publish it, we can create a build
for you for testing. See below under testing. (When you  develop your game in close collaboration
with us, we can create builds earlier; see below.)
Use good programming and documentation style when you create your game. Preferably use scripts
and code and add plenty of comments. Give your resources and variables meaningful names and
preferably maintain a technical document that describes how your game actually works. Realize that
normally the people at YoYo Games will have to do some final changes in your code to make it work
correctly on the devices. Hence, it should be easy for them to understand your code. Keep the size of
your finished game to under 10-15 MB. Otherwise it will take long to load.
There are a number of features available in the iOS runner that are not available in the PC version of
GameMaker. For example, there is support for tilting and Game Center (online leader boards and
achievements). To use these you need an extension package  YoYoGames_Extensions. This will be
regularly updated with new features. The calls in it do nothing on the PC though and are just
placeholders for the functions on iOS and Android (except for YoYo_Get_Platform). See the appendix
for an overview of the functions available. Once we have agreed to work with you on publishing your
game we will provide you with the most recent version of this extension package.