You did wonderfully at achieving convergence of the boxes. You developed one bad habit over the course of the challenge though which is to put all of the vanishing points extremely close to boxes. This makes it easier to have accurate convergence but it makes the perspective so extreme that it undermines the illusion of space. In real life one would basically never ever see a shape that looked like that (e.g., upper right corner on the image of the page marked 162--that's a salient example, but it's a trend through all your boxes especially in the later 150 or so).

Anyway, good job. Your lines are very straight and you are developing a good eye.

Hello! I am Malte. As for my refrence I work as Concept Artist in Video Games. Good job making it through :) Your boxes look believable and solid and I can also see an improvement over time. Also you have a lot of boxes really nailed down in terms of the vanishing points. That is good work. One thing you should really practise though is drawing less dynamic angles. I do not know what your goal as an artist is but comming from a concept art perspective I often try to draw designs in an almost orthographic view to communicate the design as clear as possible. Do not get me wrong there are may cases where dynamic angles are needed for example in comics (not all the time) illustrations and 2D animation. I would say just keep your goal in mind and optimise your practise towards it. Keep going you are doing good. Greetings Malte