It has a modern quad core and a decent iGPU, which means it will excel as an office workstation or as a media center PC, same as any current i5 or i7 NUC. Even the current i3 and older Gen i5 and i7 NUCs with their Hyperthreaded dual core CPUs are more than up to those tasks. Because I've been using them that way for years using OS X and Win 10, since the Broadwell days. This is not what's of interest here.
The only thing of interest here *is* the 3D gaming. If you're a serious gamer, you build a machine or get a gaming laptop. But if you're a casual gamer or want something small and cheapish for young kids, then these PCs could fit the bill.
I used my Broadwell and Kaby Lake NUCs for light 3D gaming. My kids have used Broadwell, Skylake, and Kaby Lake NUCs for 3D gaming. They are capable because they have Iris Plus GT3e GPUs in them which compete with Vega 8 or so, not the low end GT2 UHD630 which are standard for all Intel's other CPUs.
The question is how much better do the 2200G and 2400G do than the Iris Plus 655, which they should as these parts are significantly higher wattage than the NUC chips (25-45W real world usage).