Shadowfall was apparently poor, but I haven't played it, so I couldn't say what was necessarily wrong with it.
I don't really understand what people disliked so heavily about Knack. They're not amazing games by any stretch, but I don't think they're bad. There are much worse games that get less vitriol. I've seen some people criticize them for not actually being platformers. They're probably closer to e-rated God of War (original trilogy) games, than something like Crash. My kids love them at least.
There are lots of other games to play first, but I think they're worth checking out cheaply.