According to the official Xenia compatibility wiki, Sonic Generations is rated as but with caveats.
For those who own a modified Xbox 360 (RGH or JTAG), the "Sonic Generations 360 ROM" is loaded directly onto the internal hard drive. Sonic Generations 360 Rom
: To access boss keys, players must complete mini-challenges, such as racing rivals (Metal Sonic, Shadow, Silver) or utilizing friends like Tails or Knuckles to reach the goal. According to the official Xenia compatibility wiki, Sonic