Hi, I've had the same problem as others have described. I've got an NVIDIA GTX 1060 6GB, 16GB ram, AMD A10-6800K CPU (quad core 4.10ghz) Win 10 64 bit. I made sure my gpu drivers were up to date. Campaign mode runs at very low FPS when I'm above ground, but is functional on small maps (like below Mutiny Island). Cut scenes are fine. My package.json file didn't have any entries about chromium-args but I added it as an attribute and also tried disabling my anti-virus, but neither option changed anything. It seems to run worse with more clouds and when the light is dim at sunrise / sunset.
I'm running nw.exe, none of the other executables seem to do anything on their own.