Hm. I also think level design is a difficult thing. Maybe another mechanic or just making the levels a bit bigger? 

I also thought that the port feature is very cool but you didn't used it. Just for getting up a higher platform, its a bit overkill. Maybe try to create a situation that can't be mastered without this feature (and your mechanic in general) so it makes more fun to play :)

We had like the same idea but the games did came out different :) Cool thing