This used to be my graduation project.
Client: C# (can be anything else) Server: PHP (cross-platform by default) DB: MySQL
And an open source game called Flappy Bird is included! I forgot where I found it, it was a long time ago.
- Added a YouTube link showing how to bypass the authentication system and gain access without valid credentials. YouTube link: https://www.youtube.com/watch?v=PgzOeqQssig&t=8s
Have fun with it! That is if you dare look at the messiest source you'll ever see.