You're right, the "closest" thing to an emulator is using QEMU with dimtry's gcw firmware image.
Unfortunely, he removed SDL2 from the rootfs file and the emulated GPU (a cirrus in this instance) does not support OpenGLES.
However, if the new firmware with Linux 4.16+ comes out, it will be possible to use it with VirtIO and VirGL, giving us the ability
to use hardware acceleration from your host computer.
(provided that you use a linux distribution that builds qemu with virgl support ofc, which isn't the case for debian yet)
However, without a new firmware, nothing else can be done. So its best to wait i guess.
And even then, it won't be a proper emulator. For example, it will not be able to emulate the slowness of the Vivante GPU core.
But speed issues aside, it should satisfy most people.
Another reason why there's no such thing in the work is because most games (if not all of them, with the exception of MazezaM and zerox86, both of which are proprietary) are available or can be ported to PCs or other platforms.
Even Unnamed Monkey Game is planned for PCs if i'm not mistaken.