Jumping right in with your organic forms with contour curves, it appears to me that you may have gone into this without being fully aware of all of the specific requirements of the exercise (perhaps as a result of working off memory instead of double checking the instructions). Most notably, you neglected to adhere to the characteristics of simple sausages (as described here). Additionally, keep in mind that the degree of your contour curves should be getting wider as we slide further away from the viewer - if you're unsure as to why, you can review the Lesson 1 ellipses video. Lastly, while this isn't strictly required, it's a good idea to include a little full ellipse on the ends where the sausage is facing the viewer, as shown in the instructions as well.

Continuing onto your insect constructions, there's a lot here that shows that you're thinking a great deal about how the things you're drawing exist in 3D space, but there is also a tendency to put down your marks in a manner that can somewhat undermine this effect. Fortunately this is easily addressed, and it really only requires us to think more about exactly what we're trying to do with every stroke we draw.

Because we're drawing on a flat piece of paper, we have a lot of freedom to make whatever marks we choose - it just so happens that the majority of those marks will contradict the illusion you're trying to create and remind the viewer that they're just looking at a series of lines on a flat piece of paper. In order to avoid this and stick only to the marks that reinforce the illusion we're creating, we can force ourselves to adhere to certain rules as we build up our constructions. Rules that respect the solidity of our construction.

For example - once you've put a form down on the page, do not attempt to alter its silhouette. Its silhouette is just a shape on the page which represents the form we're drawing, but its connection to that form is entirely based on its current shape. If you change that shape, you won't alter the form it represents - you'll just break the connection, leaving yourself with a flat shape. We can see this most easily in this example of what happens when we cut back into the silhouette of a form.

So for example, on this construction I have identified some places in red where you've cut into the silhouettes of your existing forms, and in blue where you've either extended off those existing forms with partial shapes, or where you've added one-off strokes without really considering how they're meant to add solid forms that connect to the existing structure in a clear, three dimensional manner.

Instead, whenever we want to build upon our construction or change something, we can do so by introducing new 3D forms to the structure - forms with their own fully self-enclosed silhouettes - and by establishing how those forms either connect or relate to what's already present in our 3D scene. We can do this either by defining the intersection between them with contour lines (like in lesson 2's form intersections exercise), or by wrapping the silhouette of the new form around the existing structure as shown here.

This is all part of accepting that everything we draw is 3D, and therefore needs to be treated as such in order for the viewer to believe in that lie.

You can see this in practice in this beetle horn demo, as well as in this ant head demo. You can also see some good examples of this in the lobster and shrimp demos on the informal demos page. As I've been pushing this concept more recently, it hasn't been fully integrated into the lesson material yet (it will be when the overhaul reaches Lesson 4). Until then, those submitting for official critiques basically get a preview of what is to come.

Continuing on, I did notice that while you appeared to be somewhat aware of the sausage method as a technique, you didn't really adhere to all of its specific requirements. You frequently drew ellipses rather than sausages, you neglected to define the joints between those forms, etc.

The key to keep in mind here is that the sausage method is not about capturing the legs precisely as they are - it is about laying in a base structure or armature that captures both the solidity and the gestural flow of a limb in equal measure, where the majority of other techniques lean too far to one side, either looking solid and stiff or gestural but flat. Once in place, we can then build on top of this base structure with more additional forms as shown here, here, in this ant leg, and even here in the context of a dog's leg (because this technique is still to be used throughout the next lesson as well). Just make sure you start out with the sausages, precisely as the steps are laid out in that diagram.

Now, what I've called out here is important, but they're both things you can address into the next lesson - so there's no need to assign revisions, and I will be marking this lesson as complete. Just be sure not to read through this critique once and never again - you'll want to revisit it periodically to ensure you're working at the points I've raised here. Even consider taking notes to summarize the major things to keep in mind, so you can have them to refer to when actually working through a construction.