Congrats on completing the 250 box challenge! I'm Donhitme and I'll be giving you a critique.

Linework

Your lines are clean and confident, I can see the dots that you placed from exploring where a corner should be, which shows that you are adhering to the rules of the challenge by ghosting and measuring convergences.

I do however, see some chicken scratch where you try to go over your line. Don't do this, we want our lines to be continuous and unbroken, and executed in a single confident stroke, of which we then live with the result. You did get better with this as the challenge went along and started to execute cleaner lines, so well done, but its something to keep in mind.

Your line extensions are also present and are being extended in the correct direction, with the exception of some missing line extensions in the first 50.

The First Fifty

Here we come across a bit of a pattern. Across the first 50, you often forget the line extension at the back corner of your boxes, which is a key element of the exercise that helps you judge and measure your convergence. Luckily you picked up on the mistake nearing the 50 box mark, but you lost out on some pretty crucial line extensions that would've helped your development in recognizing convergence.

Theres also some instances where you have the vanishing point incredibly close to your boxes, yet the foreshortening of your box is really gradual. This is especially present in 35-40, and 45-50, and shows an error in the estimation of the convergence. As a general rule, having the vanishing points and page, and ESPECIALLY if they're closer to the box, means that the foreshortening is going to be dramatic, and theres a rapid convergence.

The Next Fifty

For these boxes we're pushing the vanishing point off the page, and as I mentioned previously, that means that the convergence will be more gradual. In your work however, you have a lot of instances of rapid convergence where we can see the lines, we see this especially in box 71, but its present in most of these, although you did get somewhat better at keeping it gradual as you went on. Refer here.

The Last 150

You varied your boxes and experimented with their lengths and shapes, which is good. I'd note however, that when the angle of the arms of your y (from the y-method) is less than 90 degrees, your boxes will end up with a high level of distortion, so thats something to keep in mind. You varied the foreshortening of your boxes, but definitely leaned heavier into rapid convergence/dramatic foreshortening.

An incredibly common issue (in terms of how many students make it) is some of your edges converging in a "pair" rather than thinking about how all 4 edges will converge in the same direction. Try to keep the convergence of all 4 edges in mind when performing this exercise in your warmups. This diagram can be helpful on this case.

Another mistake that you made (which is also quite common among students) was having a greater discrepancy in the convergence of the middle two edges of a given set (the ones that pass through the middle of a box). This occurs because students might overestimate how much of a difference in angle there might be, despite those edges tending to be fairly similar in their orientation. One thing that can help is to consider how those edges would meet, and the angles between them there, as shown here.

Overall

For the most part, you understood the principles of the challenge and gradually got better at judging your convergence and constructing your boxes, so well done. However, I think you missed out on some practice regarding Dramatic vs. Gradual convergence due to some mistakes in your process (Forgoing the back corner line extension in the first 50, and using dramatic foreshortening in the next 50) so I'd like to assign some revisions.

Next Steps

First, re-watch the video for the first 50, review the diagrams I sent, as well as this link for foreshortening, and then do 5 boxes in the style of the first 50. Don't forget the line extension for the back corner!

Then, watch the video for the next 50, and do 5 boxes with more gradual convergence in mind. You'll know they're done well if the line extensions are going out from the page and are converging. Just try your best at this part, don't expect it to come out perfect.

Take your time with these revisions and make sure you review the content carefully to get the best out of this critique. Once you're finished, reply to this critique with your revisions, then feel free to take a break, revel in your massive achievement, or take a stab at lesson 2 and continue your drawabox journey!