The image above is concept art for a racing game that may or may not still be in development. Painted over a screenshot (but you can't see any of it anymore). The pixelized texture is meant to imitate the nearest-neighbor interpolation algorithm commonly seen in PS1-era 3D games.
PaintTool Sai. Concept art for an amateur game that has been in production for more than a decade.
This is supposed to be a mountain-sized mech made of guns. This thing requires ten pilots to operate and the combined power of ten microplanets in orbit.