Minecraft, or even worse 3079, have made significant sales, there are people who want FPS games that don’t feel that AAA graphics is the main selling point, ****** AAA FPS games are something of a cliche.
Killing Floor is still making sales on steam, even the expansion packs still go for $5, and the servers still have people in them, and people still think the graphics for killing floor are good, because people care more about the actual quality of the character models and the painting than the technology.
The demand for retro graphics is quite high today and people actually enjoy it, I was an avid quake (1) player and an Unreal Tournament player and in those days there was an incredible amount of mods and mutators available for these games, hosted many many websites dedicated to only some of the best of these mods, I remember one sub-site had a new weapon to play with pretty much every day. That was , because you could make something quickly with the tools and we should aspire to that.
Whether you are using static meshes or not, one thing that would be nice is to customize those grid sizes.