I think there's still room for improvement but it's already ready good - one can see that you can draw. As a tipp : Try to make the colors darker so that you can add shades and stuff - That was the thing I had to change one my drawings too, it looks more realistic with different shades of grey :)
This is good because u know how to Shade which is tricky (i still cant do that and ive been drawing for 2 years) but every Artist starts like this :) keep practicing.