I played through this on the weekend and enjoyed it thoroughly. It's nothing like traditional minecraft games but I think it uses the engine well.
Thankyou for making and publishing this Wuzzy :)
N.B. I don't expect you to like any of my pull requests or want to implement anything I mention here, but I think you might enjoy reading it anyway.
Hub world and levels
Wow this game has a lot of levels. I had to draw a map of the hub to keep track of which is which.
I couldn't help but draw comparisons with Super Mario 64 whilst playing. Jumping into paintings vs using portals with decorations near them.
It took me an embarrassingly long time to realise that the decorations near each portal represented the level on the other side. That... made things quite a bit easier. I still kept using my paper map (especially for keeping track of the few level-to-level portals).
Gorgeous faux-reflection either side with the corruption occurring. It's a shame that I spent my time only looking at the central section.
This is the one level I will complain about. I thought that a light near a jumppad means it sends you higher, but there is one platform of the tower where this rule doesn't apply. Lots of frustration was had from repetitively traversing this layer and trying to remember which jumpads in the almost-rotationally-symmetric room were the good ones and which were the duds.
Level: Cube processing
One of the pathways in this level is a taunt. It shows you something, but doesn't let you reach it.
I kept expecting to be given another ability to finish this level; but eventually I realised that it was a puzzle I had the keys to all along. Cheeky bastard :)
The exploring was a lot of fun. The two types of pipe/rope create good interactions and the hidden pathways everywhere were good to uncover.
The tunnel level leading to climbing however: not so sure, felt more like work to play than fun. I skipped most of it.
Technical: Ground detection - distance
(You've already seen the pull req for this one. It's taken me a few more days to sign up to the forums because the user registration email wasn't working. I'll keep discussing it there.)
Technical: Ground detection - mismatch between minetest engine physics & player abilities
For ages I thought the lua code for dashing was unreliable and laggy. I then read the code and had a lightbulb moment, gameplay became much easier after that.
Player expectation: whilst I'm still standing on a block I can dash. When I'm falling or in the air I can't dash.
Lua scripts: you can only dash when a node is directly under your centre.
There is a big difference. When walking off a ledge you are still supported until the last corner of your body leaves the edge (minetest physics); but during this last 1/2 player width you are unable to dash (your centre is off the edge). This means there is a big deadzone around the edges of platforms where dash unexpectantly stops working.
A workaround might be to probe 5 points (player centre + 4 corners) and choose the most interesting block (activ pads, anything non-air, air) if the centre one is uninteresting.
I don't think this change would break any of the puzzles. It would make things less frustrating (easier to hit bounce & jump blocks, less likely for dashes to fail), but not necessarily easier (I don't think it would create easier puzzle solutions; eg initial dashing positions & pathways would still be the same).
Some games take this further and let players perform a jump within a few frames of falling off an edge. Albeit this is probably more important on consoles + TVs which traditionally can have a lot more input lag.
Technical: Slope traversal
Early on in the game my character walked up shallow slopes like stairs, with the screen shaking vertically. It was nice later when this stopped (was it because of the slope climbing pickup perhaps?).
Technical: Node highlighting
Turning this off in Minetest's settings made sense. There is no block placing or clicking in the game so it was an annoying distraction.
Music & SFX
In general: I really like them.
I don't think I recognised any SFX as coming from a stock source, which means you either found a nicer niche source or generated them all yourself (which is always more effort than you imagine). It was worth it :)
Music became a bit repetitive after a while. Perhaps spacing it out with some quiet segments in between repeats might be a cheap and easy way of reducing fatigue.
(Now mostly fixed): The loud high-pitch content of some of the sfx really hurt my ears, I had to turn sound off by the end of the game.