Initially the player can only use Soul to 'Focus' and regenerate masks, but as the game progresses, players unlock several offensive spells which consume Soul. The game continues from the last visited bench they sat on, which are scattered throughout the game world and act as save points. Players need to defeat the Shade enemy to recover the lost currency and to carry the normal amount of Soul. The player loses all Geo and can hold a reduced amount of Soul. If all masks are lost, the Knight dies and a Shade enemy appears where they died. By striking enemies, the Knight gains Soul, which is stored in the Soul Vessel. When the Knight takes damage from an enemy or from the environment, a mask is reduced. 'Mask Shards' can be collected throughout the game to increase the player's maximum number of masks. The Knight starts with a limited number of hit points, which are represented by masks. Defeated enemies drop currency called Geo. The player can also learn spells, allowing for long-range attacks. Melee combat involves using the Nail to strike enemies from a short distance. In most areas of the game, players encounter hostile bugs and other creatures. The Knight wields a Nail, which is a type of sword, that is used in both combat and environmental interaction. The player controls an insect-like, silent, nameless knight while exploring the underground world. Hollow Knight is a 2D side-scrolling Metroidvania game that takes place in Hallownest, a fictional underground kingdom. Gameplay screenshot in which the player fights the first boss enemy, the False Knight. A sequel, Hollow Knight: Silksong, is currently in development.

By December 2020, the game had sold 3 million copies.

Hollow Knight was well received by critics, with particular praise for its music, art style, worldbuilding, atmosphere, combat and level of difficulty. After release, Team Cherry supported the game with four expansions. It was released for Microsoft Windows, macOS, and Linux in early 2017 and for the Nintendo Switch, PlayStation 4, and Xbox One in 2018. Development was partially funded through a Kickstarter crowdfunding campaign that raised over A$57,000 by the end of 2014. Inspirations for the game include Faxanadu, Metroid, Zelda II: The Adventure of Link, and Mega Man X. Team Cherry wanted to create a game inspired by older platformers that replicated the explorational aspects of its influences. The concept behind Hollow Knight was originally conceived in 2013 in the Ludum Dare game jam. Players have the opportunity to unlock new abilities as they explore each location, along with pieces of lore and flavor text that are spread throughout the kingdom. The game is set in diverse subterranean locations, and it features friendly and hostile insectoid characters and numerous bosses. In the game, the player controls the Knight, a nameless insectoid warrior, who explores Hallownest, a fallen kingdom plagued by a supernatural disease. Hollow Knight is a 2017 Metroidvania video game developed and published by independent developer Team Cherry.

Hollow knight shade cloak