Yeah, I would agree with that, but a bit some puzzle aspects would be good, as that's a big part of Klonoa.
I've been experimenting with
S.Z.'s Klonoa Engine and was trying to build difficult levels, and it seems to be much eaiser to make hard Vertical scrolling levels than it is for Horizontal levels, so I reckon it might be good to have a lot of vertical segments of levels.