If gameplay itself is dependant on online servers, the game has to release a working version of the server code so it at least could be run by fans, or be refunded.
I replied to one of it a while ago and basically, this part is impossible since developer also "license" 3rd party backend/plugins/software solutions to make their server working. The developer do not have the right to release licensed code/api etc.
meaning, say if a backend have the free learning version of license, the developer are bound to the commercial license, which dictates if they can release code that involve 3rd party code/api.
You can't really open a android store unless you make phone and ship with your own store. Like Samsung one, it's listed in the play store contract, almost all forms of paying developer directly is not allowed. There are many conditions/steps and warnings if you tried to install apps off the play store, some of them waive your warranty. You also open the phones to potential scammer to have identical looking website and instruct users to install app that steal identity.