Sonic.exe X3

I'm a total Sonic the Hedgehog Fan much like everyone else, I like the newer games, but I don't mind playing the classics. I don't think I've ever played glitchy oder hacked games before, though I don't think I want to play any after the experience I had...
It started on a nice summer afternoon, I was playing Sonic Unleashed (I liked how Du get to explore the towns in it) until I noticed, out of my peripheral vision, that the mailman had arrived and put something in my mailbox as usual and left. I paused my game to go see what I got in the mail... The only thing in the Mailbox was a CD case...