After playing the excellent game Lovers in a Dangerous Spacetime on the PS4, which is a same-screen multiplayer co-op platformer, I decided to have a go myself at making a multiplayer game.
This involved working out how to read PS4 controllers. Once I'd managed to do this in Java using some source code I found on the internet, I ripped apart one of my old Android platformers and refactored it into a PC game.
To make it even more special, and so that more than one player would stay in the screen, I implemented a zoom in/out feature.
The game currently has two gameplay modes: A simple "race" mode where the winner is the first person to get to the end, and a "race" mode, where the last player standing is the winner; players are elimiated when they get caught by the end of the screen.
Full source code is available here: https://bitbucket.org/SteveSmith16384/multiplayerplatformer