Very difficult for a beginning programmer but probably doable
To create your app, you need to learn to code. There is not a tutorial that shows how to build your game Project. See the resources below and the MIT Tutorials
However, there are tutorials that allow you to build parts of it.
In its simplest form to build your game app you will need to learn how to skillfully use
- either the CloudDB or FirebaseDB to create a chat * FirebaseDB * CloudDB * http://appinventor.mit.edu/explore/ai2/clouddb-chat * How to: A Family Chat app built with the MIT CloudDB component <shows how to build a basic multiuser chat app * https://amerkashi.wordpress.com/2016/03/06/firebasechat/ < Hossein's multiplayer chat game
- the Canvas Creating Animated Apps * Drawing and Animation components
- virtual Screens; you can do this with Screens but if you do, your Project will need to pass a lot of data between Screens and the coding gets very complex. This is your choice. * Building Apps with Many Screens
Here are some resources to help you learn to use the AI2 tools. A very good way to learn App Inventor is to read the free Inventor's Manual here in the AI2 free online eBook http://www.appinventor.org/book2 ... the links are at the bottom of the Web page. The book 'teaches' users how to program with AI2 blocks.
There is a free programming course here http://www.appinventor.org/content/CourseInABox/Intro and the aia files for the projects in the book are here: http://www.appinventor.org/bookFiles
How to do a lot of basic things with App Inventor are described here: http://www.appinventor.org/content/howDoYou/eventHandling .
Also look here http://kio4.com/appinventor/index.htm and here http://www.imagnity.com/tutorial-index/ for more tutorials
Learn about components http://ai2.appinventor.mit.edu/reference/components/
and visit the Library http://appinventor.mit.edu/explore/library Help>Library on the MENU
Good luck. 