Kingdom Hearts Union χ
Kingdom Hearts Unchained χ
A phone game carried foundational Kingdom Hearts history for six years, then replaced its playable world with a stripped-down theatre before that app also disappeared.
Quick facts
- Existence state
- Officially Gone
- Peak stage
- general availability
- Research confidence
- high
- Last verified
What it was
A formally released online mobile role-playing game derived from the browser title Kingdom Hearts χ.
Players created Keyblade wielders in the age of fairy tales and experienced lore later referenced by the main console series.
Existence timeline
Unchained χ adapts the browser game.
The story reaches English-language players.
A major update expands multiplayer and narrative content.
Square Enix schedules the final chapters and offline transition.
Battles, accounts and progression stop functioning.
Only non-interactive story viewing remains in the revised app.
Why it ended
Square Enix ended online service in June 2021, removing battles and progression while converting story material into an offline theatre.
Last confirmed trace
Square Enix's closure notice, the former offline theatre, official videos and fan recordings preserve most story scenes but not the original game loop.
What it left behind
Its canonical importance makes the loss of playable access particularly visible within a franchise otherwise preserved through rereleases.
How we classified it
The archive unit reached normal public release or operation and is no longer obtainable in its original public form.
Verified normal public availability maps to 100 under Arrival Score V1.
Sources & verification
Last reviewed 2026-08-01. Sources are linked so readers can inspect the evidence directly.