I bought nuc8 i7-8559U CPU @ 2.70GHz / installed 16 gb ram + 512 ssd M.2.
Is this device could playing games on it?
and why VRAM shown 128MB only!
Yes, you could be playing games on it.
Do not worry about the memory. It will use up to half of the physical memory you have.
For more complete information about compiler optimizations, see our Optimization Notice.