Feel like this is missing a jump acceleration meter, so that the height of a short press can be messed with without making that of a long press gigantic. This absence is especially easy to feel with the supposed run & jump presets, Sonic's in particular.
The platforms are also weirdly finicky. The series of crates can randomly just take away all of your momentum, which gets in the way of feeling out and showcasing the points this app/game/essay tries to make. Maybe a toggle to also make the *platforms* rounded corners would've been a good idea.
There's also a weird effect to horizontal damping, where putting it at low levels feels "better", but when you run into a wall, the camera will snap back and jerk behind your character, which makes me motion sick. I couldn't find any settings combination that kept a tiny amount of it for feeling the impact of running into a wall without getting in the way of the lookahead.
I truly love the idea behind this, but I can't say the execution actually illustrates it well.