Hey there Konstantin! So, I'm seeing imgur links for 1-50, 104-153, and 154-203. While I'm sure you didn't just go ahead and skip to 104 from 50 (I'm assuming it's just imgur links), I'm still going to ask you to submit a revision with links for those missing 100 or so boxes before I mark this as complete.

Although I would like to see the final bunch of boxes, I can critique what I see here and I will say that you did quite well on this challenge! From the start, your linework is clean and thoughtful, with very few errors or deviations. I do see that you have a tendency to go back over mistakes with an additional line and I must warn you against this as it generally detracts from the drawing, but overall, you show a good deal of improvement and control with your linework.

Your convergences show similar improvement and I think you did well to have a section focused on dramatic foreshortening. This is often the 'easier' side of the spectrum, since the vanishing point is usually on the page but in that vein, it helps solidify the concept of converging lines as you move to shallower perspectives. While you do have a few stray sets of lines towards the end, overall your boxes look solid and well-constructed. Very nice work there.

We link these notes at the end of each challenge as a matter of course. They go over the angle of the correction lines as they approach the box and how keeping an eye on this relationship can help tame stray lines. Another good technique is to consider each line with respect to the lines with which it shares a vanishing point, rather than in respect to each line with which it shares a plane or a corner. This can achieve the same effect.