The Sega Shop stays busy in 2018, and releases 6 more tees to choose from, though some are just variants of each other.
The first 2 are red, and the difference is one has the Forces Uprising logo big & centrally located, while the other has it small and off to one side.
The next tee is a choice of red or blue, but it has the same white design. It's a 'sparkling' pixel-look Sonic thumbs up face with a Genesis controller and the slogan "Be My Player 2" with a heart. The last 2 are Sonic Mania, with Sonic in the geometric colorful shapes under the title, and it's a choice of blue tee or black tee.

The "Be My Player 2" seems to be from their odd 'Valentines day' kick they went on earlier in 2018. It's an odd slogan/theme to choose because the classic games weren't really known for a ton of 2-player action. Each tee here is 25 dollars in the Sega Shop & is all adults sizes.