I'd like to add a machine gun, and/or some missile launchers to it. Possible improve the shading and lighting. Also I think the wheels and tracks could use more texture and shading/lighting.

Lazur URH wrote:The top looks quite good but the bottom seems a bit off in consistency.
In my humble opinion the cast shadow is a bit too much and the wheels look cartoonish with those outlines.
It all depends on the context though, If this will be used in a game, maybe that outlined style would be better.