nice idea...
really like the lines used and the simple block shading / smudging.... however i feel that it could be touched up alot as some areas of shading dont reach the lines... its rather messy and in places just sloppy... it somewhat looks like his missing a leg under the torso... its so beefy and chunky that armor his leg doesnt seem to apear where i think it should... but thats just me... if you were to touch the shading and colours up to a neater standard... spend a bit more time doing some details and the like... (i can see you have done some) but its rather rushed in my eyes...