Sonic Unleashed got too much hate for sure, but I think it is mostly due to it being one of the most frustrating and unfair platformers I have ever seen in my life.
Pshhh, the game isn't that hard. It's a bit challenging, sure, but the challenge is what helps make it fun. ^___^
Try beating stuff like Super Magnetic Neo or the original Ninja Gaiden trilogy on the NES, then we'll talk about whether or not Sonic Unleashed is extraordinarily hard.
"Frustrating and unfair" is not the same thing as just a generally hard game. I beat all of the Ninja Gaiden games fine without much complaints, but stuff like this:
[youtube:1mmi7lgy]GMty0PE8RLs[/youtube:1mmi7lgy]
Is just downright bullshit. You literally HAVE to memorize everything in there perfectly to do it at all, and do not get me started on S ranking that bullshit. It is just horribly bad design.
That would be fine if this was not designed as a kids game... But it totally is. Not many people would find gameplay like that very enjoyable, but on top of that kind of story... It is just hard to market good.
A lot of Sonic Team games have been really awkwardly frustrating lately, it is just their style to have bad game design.