Starting with your form intersections, the first thing that jumps out at me is the quality of your linework - there are some places in which I can see a few subtle signs that you're using the ghosting method, although I don't see them across the board. More importantly though, it appears that the execution of your marks is quite hesitant, resulting in lines that waver and wobble pretty frequently, rather than remaining consistent and smooth. This usually stands out as being a sign that a student hasn't necessarily been keeping up with their earlier exercises as part of a regular warmup routine.

The ghosting method exists as a whole in order to give you the freedom to execute your marks without hesitating, and without being afraid of making a mistake, as explained in this deeper explanation I gave to another student.

Moving on, I did notice some issues in figuring out how to think about intersections with curving surfaces - here are a handful of corrections for one of your pages. It's definitely a difficult thing to figure out, but the key is about focusing on how those surfaces actually curve in 3D space. Spheres can be tricky because they curve in every direction, but the particular dimension in which you should be focusing can be determined by the other form they're intersecting with (especially if we're looking at a flat surface). In addition, being mindful of where the flat surfaces are is also important (like when thinking about a cone's base), as well as how the edges between faces will automatically result in a total change in the path of your intersection.

Moving onto your object constructions, it's very clear that there are some things that you're certainly struggling with, though I can definitely see important steps being made in the right direction.

The first issue I'd like to raise is that you appear not to be taking advantage of some of the lifted restrictions for this lesson that are listed here at the beginning. As mentioned there, you are free to use tools that would likely make your life a lot easier - from ballpoint pens and rulers (which you probably have access to), as well as ellipse guides (which aren't necessarily available for everyone, though in the next challenges/lessons it is highly encouraged that you get your hands on at least a master ellipse template like the one listed here).

This lesson is very difficult on a technical level, and is a big step from what we've been doing thus far, and so making the choice of continuing to freehand your lines here is only going to serve as a distraction from the concepts we're exploring. Some students erroneously believe that by taking the harder route here, they're going to benefit overall - and while that is an admirable stance, I'm not lifting those restrictions to be kind. It is entirely in the interest of ensuring that students are able to focus their efforts on the matters we're dealing with now. Improving your freehanded lines and ellipses is what the first two lessons were designed for, and it's why we encourage students to continue doing those exercises as part of their warmups. These lessons are for something else entirely.

The use of a ruler would be especially useful, simply because it would allow you to estimate the convergences of your lines prior to actually drawing them. I've certainly noticed a tendency to struggle with your overall enclosing boxes. While regardless of what you're drawing with, it's important that when drawing any line you're thinking about how it needs to be oriented in order to converge more consistently with the other lines it's meant to run parallel with, having a ruler can help considerably with this, since it gives you a sort of physical manifestation of the line without having committed to it.

We can see, for example, in this barrel demo drawing that there are lines that run parallel to one another across both the larger box and the smaller one, but that their trajectories appear to diverge, rather than converging in a consistent manner.

Another issue that stands out to me is that your pen appears to be very heavy. Now, there are any number of causes for this, between the sketchbook itself being smaller (thus making the marks much heavier relative to the book as a whole), the pen itself being thicker, or your pressure simply being too high as you draw. Either way, it results in linework that doesn't quite have the kind of nuance these complex drawings would benefit from. This is an area where a ballpoint pen would certainly help, precisely for the reason that we don't allow them for the earlier lessons - they're more forgiving.

Now, there are areas where you've perhaps gone too simple with your construction (like the mug, which definitely skipped a lot in regards to the handle especially - you can see an alternate approach in this demo which adheres to the principles covered in this section about curves from the lesson. That said, there are also some cases where you've delved much deeper into the steps one can take to lay out one's construction with greater specificity, as shown with your nintendo switch. Admittedly the proportions there are definitely squashed, but because the construction is much more specific and on point, it still feels entirely solid and real. This is the kind of specificity (and more) I want to see from your constructions. I'm seeing something similar in your last page as well, and this all shows that you have improved.

That said, I don't want to mark this lesson as complete just yet. Instead, I want to see you grabbing a ballpoint pen and a ruler, and I want to see what you can do when applying that kind of patience and fastidiousness to its furthest extent. I'm going to assign a few additional pages below - invest as much time as you reasonably can into each construction. Ideally, only do one in a given day, so you can commit an entire session to one drawing without thinking about jumping to the next.