is that some are inevitably much harder to dodge than others, so the difference between a successful run and a failed run feels less like it was the player doing well and more like the player randomly not having to work as hard that time.

Interesting game though, I was expecting something more like Run Gun Jump Gun but the holes didn't end up mattering much for most of the game. Really effective illustration of how much a single game can progress in difficulty. The "secret characters" were cute additions.