Game is fun. Most difficulty can be avoided by dodging checkpoints (e.g. in the castle in the sky) and then dying after collecting a powerup to return to the big open area on top of the map. Wall run still has to be obtained normally, which has a couple hard jumps, and there's some difficulty on the way to one of the other powerups I don't quite remember which.
Also walljumping is fun and lets you access areas early and get out of areas you aren't supposed to get out of yet and zoom up elevator shafts. To wall jump, after collecting the jump power-up jump into a wall and then hit both the movement key to go into the wall and the jump key alternatingly very quickly. It works much more easily in elevator shafts and other one-tile gaps where you can just button mash.