Hello again!
So, I took back my gamepad from the kid, discovered that I didn't quite vibe with the default bindings for an XBox style gamepad layout (having all the character controls on the left hand except the jump button, which had to be handled by the block control hand, didn't work for me at all), but that was easily remedied. And indeed, the game was clearly easier to control this way, and I scored better. I still mostly felt stressed out, not achieving and kind of "flow". I think maybe the game should be way easier to start with in the beginner mode, the actual act of building the road ahead with blocks and jumping on it is actually kind of fun by itself, I don't know that you need the time pressure and adrenaline surge on top of that very quickly.
I did find myself with enough time to actually try and build some lines. There's a real feeling of urgency with building as quickly as possible to get away from the wall of death, and a slight mismatch with the need to construct lines that ultimately destroys your path forward. I think this is good, it makes for important choices.
I don't know that I quite like the way the lines shake as you approach 10 blocks, it does signal danger to the character, which is reasonable, but completing lines is mostly good, and signaling danger for that feels wrong. I would go for something less "stressful" to signal that. On the whole, I think a way for the preview (which is very useful) to clearly show that dropping the block there will indeed remove the line, would be useful. In Tetris it's very obvious when lines are full, with the walls being there... in this game I found myself not having the time to count whether I'll end up with 9 or 10 blocks, which is a crucial difference.
I did indeed look at the "how to play section", both before playing at all, and after playing a bit, at which point I found it more useful, having some frame of reference. And then again later to make sure I understood correctly. Thinking about it I might suggest that something akin to the "dev plays" video should probably make up most of the main menu? To get the player a general feeling for the "shape" of the game to make it easier to understand the actions the "how to play section" refers to. And somehow I missed the "10+" blocks to complete a line text, I think with the general number of... numbers on that screen... my eyes sort of glossed over that piece of information. I'd make it extra big and put it mid-sentence so that it can't be so easily skipped over as "something before the sentence".
I don't know if that was helpful, teaching this game is an interesting challenge.