Great color rendering of materials. I'd like to get a sense of the scale, possibly with a faded background image or terrain. Along with scale it's unclear what the tank shoots, or the scale of that ammunition. I like the idea of a triangular shaped exit point to fit the barrel shape. The open circuitry in the barrel is a cool detail but unlikely for a war vehicle. I'd also like to know what makes it mobile. It looks like it hovers, but it's not completely clear. Overall, obviously great work. Keep it up.
Some of my favourite tanks of all time were the hovertanks from Battlezone 1. They were GEV whereas this looks more anti-grav or maglev and of a much higher tech level, but this gives me the same feeling of looking at brutal power contained within an armoured shell. I like the way you have dispersed the ID markings too. Great work.