Cut out the cardio bro! I'm more on the side of those who congratulated you... Obviously at 15 you're a bit of a late-bloomer but I would kill to have definition like you. My advice: Keep up w/ the...
I agree that the fact that it wasn't a full range of motion takes away from it, but I do think it's pretty good for your size. Do it with full stamina next time and prove...
But think about it... if you are putting on more muscle than fat, then by default you are lowering your bodyfat percentage even if you are adding fat... by cutting you lower your bodyfat percentage...