From an outsider perspective that is kinda what your's and Sojourner's posts sounded like. I mean, I would say that 2012 XCOM and Sonic 2006 could have around the same level of difficulty in a very broad sense, except XCOM does it by providing the challenge of keeping pace with the aliens as they start relatively strong and just grow from there while you start off with basic weapons that pale in comparisons to what they got, but the game will do its best to provide the knowledge you need in order to fight effectively along with providing a generally cooperative UI and camera, while Sonic 2006 provides "challenge" in the sense that you will be struggling against the terrible controls (have fun doing 3D platforming when everything feels like someone just typed down settings that seemed right and called it a day), the terrible camera (3D platforming, with an inability to see where you're actually going!), the terrible gameplay decisions (instadeath vacuuming balls that appear in locations you will barely be able to see before they form, placed in a set of levels that will result in you doing them over and over and over for hours ), etc etc. In other words, one of these games provide challenge in the sense that it's fun to try your best in the game, even if you'll lose here and there along the way, you don't feel like you've just been asked to do something unreasonable. The other one provides challenge in the sense that it feels like someone just asked you to sit on an angry honey badger for six hours. They may result in the same level of difficulty being delivered, but one of these does it in the far more optimal and least customer losing way. And so far it seems like all the changes in KSP have been to ensure the challenge being delivered is the former rather than the latter. (Granted it wasn't much of the latter in the first place but there's always room for improvement somewhere.)