Eh perspective
The perspective is bothering me, you got some of the concept of a vanishing point down, but things don't seem to add up exactly. When doing something with this many lines going to a vanishing pioint, it's critical to take into consideration how much "line checking" you have to do to make sure they all go to where they are supposed to.
There are multiple problems with the character art too, the arm that's foreshortened is not contorted correctly, the arms length is off, because you decided to foreshorten it, the skew of the arm needs to be closer to the bend and the forearm is too long to accomodate it, making him arm longer than it should be, while the proportion of the arm and the hand seem wrong as the slope of the arm to the hand is not there and the bends you put in the arm (maybe for muscles) make it odd.
The reason the hand looks odd is the thumb, of course it could be just the design of the character, but the way the thumb is bent and how big it is does not compute for me.