Latest kernel (hence driver), mostly. For most people Linux Mint is great distro that mostly works out of the box. However, for gaming, Linux Mint is one of the weakest since they tend to ship old kernel.
We have to understand that gaming in Linux is in very active development right now. Having out of date kernel can make you unable to use some device, or having less performace than those with latest kernel.
Hovewe, if you are happy with Linux Mint and see no problem, it’s okay to stay. It has great community and the developers are awesome.