On the OSX version I just seem to be stuck in a pink void where there's a pearly bubble above me and the borderline logo off in the distance. I'm on a 2017 iMac with an R580 running the latest version of macOS, build downloaded just a few minutes ago. Also it complains about being a 32-bit app at startup.
Can you try the new "CPU Only" version ? It simply moves the terrain generation (which looks like being the problem here) from the gpu to the cpu.
Hmm, well, terrain appears, but it changes every frame, and it runs at about 1FPS.