Alienation is an action role-playing shooter video game developed by Housemarque and published by Sony Interactive Entertainment for the PlayStation 4. It was released in April 2016 worldwide. The game is an isometric twin-stick shooter in which one to four players defend themselves against an alien invasion on Earth through increasingly-difficult levels. Players can choose one of three character classes, each with its own abilities. Players can upgrade their weapons with collectables, known as upgrade cores.