Sega Dreamcast was ahead of its time when released in 1998. It was the first console with a built-in modem for online gaming and featured impressive arcade-quality graphics.
Lighter games and arcade ports (fighting games, 2D-heavy titles) run reasonably in Flycast; demanding ones such as Shenmue II slow down noticeably. Community tests on an R36S rate Crazy Taxi, Power Stone and Sonic Adventure 2 Good. The same holds on every R36 model, because they all use the RK3326 chip.
The chip is the same in every model, so the rating is too. What differs is the screen: 4:3 panels suit most home consoles, the 1:1 square panel suits Game Boy and GBA and shows 4:3 games with bars.
The R36 handheld family runs Dreamcast titles with limited compatibility out of the box.