I basically want to know whether or not it is possible to copy a mobile game and make it into a new game by modifying it . I want to be able to access , moderation tools and basically alter, things like characters, events, in ap purchases etc. Alter it to make it different enough from the original and make it available to other users. The game I want to copy is no longer in the play stores and I want to change that.
Is it technically possible? Perhaps. You could disassemble the APK, but when it relies on any server-sided components, you would have to clone those yourself. But taking a game executable made by someone else, doing modifications to it and then releasing it yourself is a copyright violation. It does not matter if the game is still being maintained or even if it's still available on the market. Copyright expires decades after the death of the author. It also doesn't matter if you changed a bit of stuff to make it more original. If there is just a tiny bit that remains from the original, you are violating the copyright on that.
"But what about all the other people who are doing that and their ripped games stay up?"
There can be a variety of reasons why the copyright owner did not take actions yet:
- They are not yet aware of the violation
- They lack the legal awareness of their rights and how to enforce them
- They don't have the time or money to deal with it
- The violator and/or the platform they release on are in some country where the copyright owner can not reach them
- They don't care
But whatever the reason might be, you can not count on the same reason to apply to you.
So when you like a game and would like to create your own version of it, then you have to start from scratch. You can not reuse any assets or code from the original. You have to recreate them yourself. For more information about how closely you can stick to the original without getting into legal hot waters, check out the question "How closely can a game legally resemble another?".