Hi Allipses! Congrats on finishing the challenge! It's been a real battle I'm sure but you've finished and that's great.

So first of all I'd like to draw your attention to the line extensions; they're rough. A lot of them are missing (45-74; 99-106 etc) and there's a few examples of them being extended in the wrong direction (139; 144; 176). There's some times you did the extensions correctly, at around 116-119, but they're few and far between.

As for the boxes themselves, they started off really rough i won't lie, but slowely you improved, especially around 200 or so. There's still a few ones that are really rough still(219; 222; 231 that back corner), but it's much better than we've started.

You also draw a lot of the boxes in the same orientation. When following the initial Y on the Y method, the length of the lines of the Y can have any proportion, the right line can be super long and the other ones be super short etc. And same with the angles, the combination of angles between the lines of the Y are limitless, as long as the angles are always over 90 degrees. Take a look at this diagram. It shows different orientations that your boxes can have. Take inspiration from it, but don't copy. The boxes you draw are meant to come from your imagination.

You drew both shallow and dramatic foreshortening, variation is good, keep doing it.