There's not much to go off here, but from what we can see, this N64 emulator looks like it's shaping up to be solid.
The strangely named 3G4 was developed by a 14-year-old, believe it or not. I don't know what mojo this teen is packing, but Super Mario 64 looks to be running nicely in the above video. We hear that the emulator runs pretty great so far. There are issues like duplicate button registers, delay of presses, and crashes when heavy gameplay occurs, but those are being looked into.
This certainly looks to be running better than any of the early 3D console emus I've seen.