Here's a long sleeve kid's size shirt from Segaworld Sydney. While it existed, Segaworld had quite a selection of clothing, including some things that weren't that common. Sonic was mostly a 't-shirt' type design, but they used sweatshirts and long-sleeves as seen here. The shirt is rather plain though, just all blue smooth cloth with the foreward-facing Sonic stock art head on the front inside of a green patch. While the shirt isn't very artistic at all, it is uncommon.