Well it was a pretty good attempt. I'm not sure why you felt that way about it.
Not that I can do any better (or even close to that) but I can say that with little more practice you can get the dimensions improved (this is usually the hardest part in drawing as far as I know).
Generally speaking, however, it was a very decent graffiti! And I really encourage you to keep at it and not stop with this. As I see more than a mere "attempt" in there.
Your non-bs friend
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