The sheer unfinished nature of some of the features, especially the bracelet gems that could literally allow you to out of bounds any area.
The horrific glitches with physics that often caused you to fall out of bounds, through floors, or fly off into enemies. The constant, never ending loading screens at the start, end, and often even in the middle of cutscenes. I'd just come off the back of a Sonic Adventure 1, 2 and Heroes marathon, and felt like I wanted more. When I picked up an Xbox 360 way back in 2007, the only Sonic game that was available for the console at the time was the much hated, much panned, universally considered terrible Sonic The Hedgehog, or 'Sonic '06' as it is known, to avoid confusion with the actually good 1991 cartridge release.
I've never quite managed to get to Japan to try Waku Waku Sonic Patrol Car, but anyway. The original on the Sega Master System was the first video game I ever played, and I've completed every Sonic game released every since, no matter how obscure. As anyone who knows me will tell you without hesitation, Sonic The Hedgehog is probably the biggest most influential video game series in my life.
