I was able to see the imgur album, so don't worry about your submission. I did notice that some of your boxes are not numbered individually, so not all examples will have numbers.

For the first 50, your lines are clean overall. However, I did see some wobbling throughout the set. Your convergences also show good accuracy, though I did see some lines pair off and converge towards two vanishing points, like in box 5, box 21, and here.

For the next 50, your lines show improvement. Wobbling is still present, but most instances are less dramatic overall. Your convergences also show improvement in accuracy, though there are a few more instances of lines pairing off, like in here, here, and here.

For the last 150, your lines continue to improve, with wobbling further reduced towards the end of the set. However, since it was present throughout the challenge, I do recommend reviewing the information in this section to ensure that you're practicing the proper technique.

Your convergences also continue to improve, though there are still instances of lines pairing off, like in here, here, and here. In these boxes, the inner lines (green and orange in this diagram) diverge instead of converging at the vanishing point. Keeping in mind the angles of neighboring lines can help when planning the box's construction.

As an aside, here has some lines extended in the wrong direction. Also, some of your boxes are missing some line extensions, including: box 12, box 20, here, and here. It's not a major issue since it didn't happen too often. However, I noticed that, in the latter half of the third set, many boxes were missing some extensions from the back corners. While it is true that we tell students not to worry about the back corner, we still want to draw extensions for every line. Be sure to double-check that all lines are extended correctly going forward.

On a minor note, as mentioned above, most of your boxes were not numbered. I also saw that numbering restarted at 1 in each set. For future reference, it's better to number individual boxes on the page. This makes it easier to call out examples and keep track of progress through the challenges. For the same reason, we prefer to have boxes numbered consecutively (1-50, 51-100, 101-150). It's especially helpful if submissions end up in the wrong order, which happens from time to time.

All said, I'm going to mark this challenge as complete.