Ok! I will try to be brief in correcting your 250 boxes.

Also, congrats on completing the challenge, really looks good progress over all.

Still, we will always observe a few details:

Lines:

If you notice, several of your lines wobble in your boxes throughout the challenge.

As I see it is somewhat consistent. I will remind you that the lines have to be drawn securely (so they don't wobble) and with the entire arm movement.

A look at lesson 1 may remind you how to draw lines correctly with your arm.

You applied cross-hatching; but I can't be sure if you also line weight, sometimes the camera doesn't register it much.

Line weight is very important to learn because of its constant use in other lessons.

If you haven't applied it, I leave you a couple of images on how to do it correctly:

https://imgur.com/OHvr7Mb & https://d15v304a6xpq4b.cloudfront.net/lesson_images/980a575e.jpg

Box construction:

Most of your boxes converge to their vanishing points, which is very good as they can sometimes diverge from that point.

It is also good that you have played a lot with the orientation of the boxes, as this will be very useful in the following lessons.

I see that you drew boxes with sharp and light foreshortening alike, this is excellent stuff. In the next lessons it will do you good to stick more to light foreshortening, since you will be working with objects of common scale and view.

I might mention that in some boxes, your lines converge in pairs, as shown here:

https://imgur.com/KSHwTwo

This is somewhat incorrect, as you will want all your lines to converge to their corresponding single vanishing point.

When you think about the relationship between each pair of lines and the angles they form, it may help you to avoid the above mistake.

This diagram may help you:

https://imgur.com/8PqQLE0

Overall, very nice work.

I'll leave you some homework to improve on these details,

and I want to remind you not to rush it, you will correct everything better

by going slowly.