Sonic Unleashed had excellent art direction, was a wonderful debut of the Hedgehog Engine + Light-field, had great NPCs, had some good quests, had good daytime level design, and had an excellent soundtrack.
The only issues with the Werehog were that: the balancing is shit and it shouldn't take you 20+ minutes to finish off a level despite looking for medals. You should not have to level up Werehog by grinding and cheating the system to max him out in order to finish off an Act in a short time. It was also kind of slow and clunky. Make it faster, axe the grinding/levelling, and possibly replace him with the Knuckles model and maybe it would be alright.
Eggmanland HD was also a weak point and it's better in the SD version. Looking for medals in the HD version detracted from the overall flow of the game.
But despite that, I love Sonic Unleashed. I think it's perfectly playable.
...ok, I relent, we both like iffy games. Hahaha.