I also like that the creator (Gumball) uses the Fleer logo for their name. Very nice touch.
I never saw a USFL game in person, but do remember watching some of them on TV. Since I was not born when the AFL formed, and too young to remember the WFL, it was exciting to see the start of a new league. Its a shame the league wasn't able to survive.
If you haven't seen the ESPN 30 for 30 documentary "Small Potatoes: Who Killed the USFL", I'd highly recommend you check it out. Its a great look back at the league.