After the enjoyable but flawed Sonic Heroes released by the end of 2003 in Japan and start of 2004 in other regions with mixed to positive reception, Sonic Team wanted to attempt a different take on the franchise. Since Sonic games were and are largely targeted toward younger audiences, director Takashi Iizuka desired to catch the attention of an older audience for once. Logically so because, at the time, the industry had largely shifted from cartoony and child-friendly games, to mature, edgy and deep games more and more.
Series producer Yuji Naka stated in an interview that Shadow the Hedgehog was chosen as the starring character for this new game due to his popularity amongst fans, and the addition of darker story elements, vehicles and weapons would have made it an inappropriate act to label it a Sonic game, and then sell it as such. The concept was seen as ridiculous when people witnessed the first trailers in early 2005 and they had no idea how it was all going to play out.
Later down the year in the holiday season, Shadow the Hedgehog came out for the Nintendo GameCube, Sony PlayStation 2 and Microsoft Xbox for them to find out. Critically the game wasn't liked with the PS2 version averaging the lowest at 45% on Metacritic and the GameCube version averaging the highest at 51%. Review scores aren't everything, but with those numbers, Shadow the Hedgehog was viewed as the low-point of the entire main Sonic line-up until Sonic the Hedgehog 2006 came along.
To this day, however, there are fans who will argue it is in fact inferior to Sonic 2006… If that doesn’t speak volumes, then I haven’t got a monkey’s what does. All I knew was that I played Shadow the Hedgehog back when I was a kid and got every single A rank, so I must've seen something in it. Does the same apply at my age of 19 now? Well, I'll do my very best to provide a fair look in this video at Shadow the Hedgehog.