I like the style you got going in the cartoon sketches. However you seem to be applying that cartoonyness into the life drawings. Try to focus on the natural organic lines in the figure when you do studies; you'll find that things in real life aren't quite that sharp.
I really like the last one - nice crisp lines and cute character designs.
I agree with Toxdel about the life drawing: your stylizing is good, but if you had a really tight grasp on anatomy, it would be even better. So I would suggest trying to stay true to reality when studying it, and once you've mastered that, take it to the next level with your style.
Nice sketches. I like the anatomy studies, but I'd love to see some more finished pieces with color. In the first post, the second drawing seems to have arms that are too skinny for the rest of the body. I'd like to see more stuff from you.