Atomic Heart released on February 20, 2023.
While the release window was originally set and later confirmed as being in late 2022, an announcement that Atomic Heart would be published by Focus Interactive described the game as "initially planned for 2022." Around this time its Steam page changed from an explicit 2022 release date to the more vague "this Winter." But a trailer we finally confirmed Atomic Heart's exact release in February 2023.
Atomic Heart is a day one release for Xbox Game Pass.