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.
I think making hard horizontal levels would be an art in and of itself.
I totally agree with that, I wasn't meaning to discourage trying to make difficult horizontal levels, I was just pointing out that doing it vertically is a little easier, probably because Klonoa's mechanics are mostly about jumping and reaching higher places with the help of moos.
I wish I was good at level designing, but alas.
I wish I was too, it would come in handy. Problem is, I don't know how you could possibly learn such a skill.