These would be great!
If they were real. Here are 3 ideas for Sonic Boom theme clothing, including a set! The first is a 'rivalry' themed "VS" tee. It's got one Sonic sleeve & the other Eggman sleeve. It features Sonic & Eggman in a stare-down as its design. The middle is an all-Eggman shirt with him in his Boomstyle Egg o Matic, along with Orbot & Cubot. The sleeve has the Eggman symbol on it & the logo is small at the bottom corner.

A set for girls? It would likely be popular if it gets made. This has a fun Amy theme, with pink tank top and large Amy w/hammer jumping graphic. The matching pants have pink cuffs & waist, with a scattering of words, logos & character art. The light green in the pants & on the shirt border helps tie the design together. These are well-thought-out items with some nice fun designs. Hopefully these get made at some point. Write in if you see one in stores!