There's a kids' TV channel in the UK called Pop and it basically syndicates all the French and Canadian imports CN doesn't want. back in the 2000's they reran the 90's Sonic cartoons for some reason, mostly AoStH, sometimes Underground and once in a blue moon SatAM. anyway, at that time, they put the Ultimate Flash Sonic fangame on their website and even I, being a 6 year old who had never played a proper Sonic game at length in his life at the time, could tell it wasn't official.