I think everyone's falling into the old trap of "people who like this must like it for X reason" again. Personally I'm not a fan of the Adventure era games (Chao Garden excepting) and I love Unleashed entirely for gameplay reasons. The day stages are the best the series has ever had, the night stages are tolerable and don't need to be replayed to replay the day stages. I also like Colours and Generations for (attempting) to push that gameplay forward, although both fall short of Unleashed's day stages by trying to force in slow platforming sections that simply don't work in the boost style (but Colours at least has Wisps and a scoring system to keep things interesting and add replayability). If it were a full game of day stages of the same quality as Jungle Joyride 1-2, it would probably be my favourite game of all time. And I couldn't give a shit about the plot.