I would like to know if there is a good open source project that let's me run a copy of a game on my phone without crashing or bugging out after a day or two, nothing on the app store works well enough. I just want to enjoy multiple accounts on an old 32bit mmorpg from 2013-2014.
What "32 bit mmorpg from 2013-2014" are you talking about? This could be an emulator thing, or this could be a multi-user account thing, or it could be a profile-isolation thing...
Many ways to solve this problem if we had some sort of starting point.
The games called Iruna Online, account is tied to your gmail. The way to switch between accounts is the clear data on the app, select a different gmail, and redownload game data every time.
Android specifically has user accounts you can add to your phone for this.
Additionally, Xiaomi, Huawei, Samsung, and OnePlus also have similar types of virtual space environments, that they brand as Private Space, Secure Folder and Parallel Apps, respectively. All 4, of these, are based on an Android OS feature for supporting multiple user accounts, but with some customizations so that these virtual spaces are like an anonymous user account.
Unfortunately I think they require that the application be marked in its manifest as supporting these types of things, and you may need Root in order to force the functionality on this particular app. I did this with Ingress at some point after they banned me claiming I was cheating and gps hacking (probably my bad Nexus 6 GPS that liked to jump around a lot) -- because they have similar functionality. Account tied directly to your gmail.
If you search that on google play you will get a lot of results, I actually don't fully understand how it works but it basically let's you have a copy of an app with separate login credentials
True, for just the seperate app this works. Other App cloners would change IDs and shit to make that work, no idea about signing keys or updates. Work profile is the only stable way, apart from seperate profile