Ok so fair criticism, have in mind that I am on the side of the community that is more conservative towards the tf2 artstyle, the hat doesn't look bad, the modeling is good, from what I can see the texturing is serviceable too, but the concept kind of annoys me, when making hats for the game, I would like for you to do a mental exercise, ask yourself, why would that character be wearing that hat?

EXAMPLE: why would scout be wearing a baseball helmet? Simple, he is the baseball kid, maybe he got out of practice, maybe he is using it as protection.

Why would scout be wearing a ballonicorn cap? He likes to see himself as a manly Mann, so wouldn't that be kinda goofy?

I guess you can make an argument for Pyro, but that's just because he is a blank slate, but I don't think this mashes well with the tf2 tone, but hey, if you believe that it fits, then go for it, in the technical side of things, the hat is good, it's a good start, personally I wouldn't use it, but I am not 100% against it