A sequel, Hollow Knight: Silksong, is in development. Hollow Knight was well received by critics and has sold over 3 million copies as of December 2020. The player is the Knight, a nameless warrior uncertain of their own identity or origin, who wanders and explores the ruined kingdom of Hallownest to uncover its mysteries, encountering various friendly or hostile bugs, fighting bosses, and unlocking new powers and abilities to progress. Development was partially funded through a Kickstarter crowdfunding campaign, raising over A$57,000 by the end of 2014. It was released on Microsoft Windows, macOS, and Linux in 2017, and on the Nintendo Switch, PlayStation 4, and Xbox One in 2018. Hollow Knight is a 2017 Metroidvania action-adventure game developed and published by Team Cherry.