Also, how do I verify that this fork isn’t malware wrapped in emulator code?
The code is open source, you read it all, ensure that you download exactly the code you read, and you compile it yourself. That’s the only way, in general, to accomplish this.
Rocket League. Games are quick, you can play one or many in a session. I don’t know if epic has ruined it yet, but last I played the good old core game was still there.