As much as I enjoyed Challenge Mode (highlight of the entire game imo), the
recent thread on this style of game (bite-sized consistently high-challenge levels with no penalty for losing) highlights the reason why, at the end of the day, I'm personally not going to enjoy it as much as something like Lost Levels. To me, things like the challenge stages are something you tend to eventually bang your head against until you get lucky and beat it once, then never play again (and especially so with no leaderboard function). That's pretty much exactly my experience with
Don't Touch Anything. There was a short period of experimentation figuring out exactly
how I was supposed to play it, but once I had that figured out, it was just a matter of constant retries until I got lucky once. Doesn't really feel like I got any better as a player in the process and truly achieved anything other than checking another stage off the list.
On the other hand, I can dust off Lost Levels once in a blue moon and really feel engaged the entire time I play it, despite the fact that NSMBU's challenge mode has several individual tasks that really go above and beyond anything that LL ever asks you to do. I just like the structure of a "long" (for a single-sitting), moderately and consistently challenging adventure with a consequence for losing strong enough to force you keep up the pace. The threat that the
game can beat
you is valuable to me, can push you to play harder to make up the difference whenever you mess up, and give you higher highs because you have to overcome lower lows. Something with the structure of NSMBU's Challenge mode can't ever achieve that, even if it's fun for what it is.
So I guess, if I wanted them to take this a step further next time around, I'd prefer some kind of expert mode for the main campaign over something like this, even though this was also cool. Something like forcing you to play through the game with no power-ups the whole way through (small Mario run), if not a set of alternate, more difficult stages. That's a big reason why I like multiplayer in these games so much, actually. Being paired with a group that I have to take extra care to coordinate and cooperate with goes a long way to keep the game challenging and fresh every time I play it.