Recognize a storage problem
Suppose ORBIT worked disconnected last week but now cannot open without a connection. That does not necessarily mean the game has removed offline support. First check that you used the same browser, profile and game address as before. A different context may never have had the files.
Browser storage is not an unlimited permanent archive. MDN documents that browsers can evict stored site data, including under storage pressure. ORBIT cannot promise a particular retention period or override every cleanup choice made by your browser or device.
Recover the playable files
Reconnect and open the game in the context you want to keep using. Allow offline preparation to run again, then repeat a disconnected launch test. Downloading the current game can replace missing program files; it does not recover a deleted personal record from an ORBIT server.
If the device is short on space, review your own storage situation before relying on a large set of offline websites. Do not choose the game’s saved site data for deletion unless you intend to lose the progress stored there too.
Build a realistic routine
Before travel or an expected connection gap, make a fresh test through your normal launch route. This verifies the condition of the files now, rather than relying on a Home Screen icon that can remain visible after something about storage changes.
Keep a screenshot of a score if you want a personal memento, but do not confuse an image with a restorable save. ORBIT has no account backup or supported progress import. If both records and offline access vanish, investigate the storage context before starting cleanup that could remove more evidence.