I just read your essay from the 4th. I often wonder about the balance between challenge screens and non-challenge screens. Thinking back to Nifflas' work, his levels are mostly non-challenge screens but highly regarded. I can't copy his ratios when I'm not copying his overall gameplay style. My levels are mostly story driven with single locations for power-up collection. In that style connecting screens can quickly become the dreaded running-back-and-forth-through-places-you've-seen screens.
In general, I think I'd shy away from copying Nifflas' style, or, at least, copying his more expansive levels (The Machine and A Strange Dream). While fairly enjoyable to play, those levels start to drag when it comes to backtracking, and, like many expansive levels, every time I hit a fork in the road, from the start 'til about the halfway point, I have to wonder, "Am I going the 'right' way?" There'll be times where I'll try heading down another pathway, intentionally avoiding multiple save points, just to see if there's anything that way - and if there isn't, I jump into some water or press ctrl+R or whatever else.
If you choose to relax and just play those levels to explore a fairly nice-looking, nice-sounding world, then that's fine, Nifflas' levels do that much better than I could ever hope to manage, but I find that the challenges are sparse, and, furthermore, generally don't scale well against the player's powerups because there's so much retreading that has to be done. In Deep Freeze, especially, most powerups
completely invalidate older challenges due to how the Double Jump, High Jump, and Climb are all complete upgrades rather than sidegrades (which the Hologram and Umbrella come much closer to), and so it becomes pointless to have the player backtrack through the vast majority of the level. The other reason I've almost wholly avoided backtracking is because it makes the minimap much, MUCH easier to have a handle on once the player gets their hands on the Map powerup. I want the player to always be confident they have the tools they need to approach a task, except when it's blatantly obvious that they don't (which, given the level's core mechanic, seems very important to me).
That said! Deep Freeze's constant challenges and puzzles, while I enjoy them, can be their own sort of pace-killer if the player keeps hitting speed bump after speed bump after speed bump, and so I think Nifflas' levels are especially good at showing that you don't need
every screen to be a challenge for the player to have a pretty good time - but it can hurt if you have to traverse over them multiple times.
(Nifflas' other levels are fairly short, and extremely linear by comparison to the two aforementioned ones. This may say something about a relationship between degree of linearity and ideal length - at least for Nifflas.)
I'm very interested to see this opening area you made to train new players. I usually try to emulate bad players with poor reflexes when I test stuff, and I try to introduce new concepts and types of challenges before I combine them into true challenges, but I never considered trying to train people to play.
It's nothing
too complex - mostly just a large series of safe jumps, lots of stair-climbing, and much more forgiving timing than everything afterward. It's also an area where I can force players to get to grips with the fact that you can actually be just barely off a ledge and still jump - something that's not exactly intuitive.