I'm a big fan of Nifflas and his work. I've played all the games that he has released so far and I loved the Knytt games. However Knytt Underground just can't keep me interested. I think I'm getting old because I just don't feel like struggling. I guess I prefer my games to be more casual these days. Then again I do like challenging games like Dark Souls if they can hold your attention and make you want to beat them.
Knytt Underground is huge. Nifflas has put a lot of work into this game and it shows. The hugeness turns me off to be honest. Previous Knytt games were relaxing and it was just so much fun to run around and explore. With Underground there's a much bigger purpose and the whole relaxing part is missing. Now it feels like grinding through the big map.
I want to be entertained. My time is limited. I really wanted to like Knytt Underground and I can see it appealing to some people. It's just not my kind of thing.