The game was developed and published by American studio
Thatgamecompany over the course of seven years, developing a custom game engine based on their previous work on PlayStation titles, to initially support the
Apple Metal API, later expanding it to add support for other platforms as well. The game servers are hosted on
Amazon Web Services infrastructure (credited in-game as AWS), with parts of the backend being written in
Erlang in cooperation with Amber Studio.
Seasons and events Sky features ongoing seasonal events, with new storylines and unique spirits and items. Seasons and events follow a
freemium strategy, where some of the cosmetics sold by spirits require a paid "Season Pass" or via microtransactions from the in-game shop. The seasons have a unique currency called "seasonal candles", which can be used to purchase seasonal items and are converted to regular candles when the season ends. Seasonal spirits may return as "Traveling Spirits" in the future, which players can give their candles and hearts to receive seasonal items for a limited time, albeit at a higher price.
Music Sky features an orchestral score composed by Vincent Diamante, with some tracks performed by FAME'S Macedonian Symphonic Orchestra. Norwegian singer
Aurora also provides the vocals for the intro and outro songs. The game utilizes
FMOD for dynamic music and sound playback. Four volumes of soundtrack albums have been released. The first volume covers more recognizable music from the base game cycle. The second volume contains mostly
ambient background music, and the third includes various pieces composed for
Sky's Seasonal Events.
Charity In 2020,
Thatgamecompany held some in-game events in support of charity. The first was the "Days of Nature" event, in celebration of
Earth Day, during which a unique
IAP (in-app purchase) was available. Proceeds from the IAP's were used to plant one tree per purchase, in partnership with the OneTreePlanted charity. This event resulted in a total of 40,576 trees planted across the Amazonian and Australian forests damaged by wildfires. In April 2021,
Sky hosted its second "Days of Nature" event, using the game to promote awareness towards
plastic pollution of the ocean. In May 2020, Thatgamecompany hosted a "Days of Healing" event to help raise money for the
Médecins Sans Frontières organization, after which Thatgamecompany donated US$719,138 to the MSF
COVID-19 Crisis Fund. For the event, Thatgamecompany also joined the
World Health Organization's
#PlayApartTogether campaign. ==Reception==