While Sonic Colors seems t' be the first decent Sonic in a while... I'd definitely make sure Sega isn't pulling yer leg before jumping into the buying process.
Take the money nas, it might be the only money ye come across in a while, 'n there be plenty a games coming out that look like safer 'n more high quality guaranteed than sonic colours. For example, skyward sword, DKC returns, or ye could save up another 150-200$ t' buy a 3DS