Ghosted Lines: Slight arching present in longer lines, just remember you can arch in the opposite direction to counteract this. Besides that solid line quality and confidence.

Ghosted planes/Ellipses in planes: At times you're ellipses will fall short of their correct placement. Keep it in mind moving forward.

Rough perspective: Next time you attempt this exercise, don't extend your lines past the horizon line so that you can more easily evaluate your mistakes. It's also worth mentioning that sometimes you went over your lines attempting to correct them and even crossed out one. In drawabox we are not supposed to go over lines like this. No matter how off a line is, we should just treat it as if it were correct and move forward.

Organic Perspective: Remember to keep the rate of foreshortening consistent. Optionally, you could've also used line weight to help communicate which boxes are in front and which ones are behind.

Conclusion: Very solid submission, you are more than ready for the 250 box challenge. Just keep in mind some of the notes above while you warm up with some of these exercises.

Best of luck moving forward

-Slyx