Hey Ralidon,
This character is pretty good. I like your design, and the execution is not bad either. I am going to go from the top of your post down, and offer any insight that I am able to, hopefully some of it will be helpful for you.
On the idle frames, the anatomy is pretty good on the angled frames. One the frame of him facing towards us, it looks like he is pushing his knees together. Frame #5 of the first animation seems like a good stance for him facing forward. Both feet don't need to point directly forward, and he should spread his feet for a more balanced stance, like in the angled frames. His torso seems to skinny, especially compared to the arms, which look too stiff. In his angled frames, he looks very relaxed and natural, but then in the frame facing us he looks like he is hunching over. Perhaps move the arms in a tad closer to the body. Also, I would slope his shoulders down, that should loosen him up a bit.
On the first animation, I'm not quite sure what he is doing. I'm not saying this is an error, as it would probably make sense in context, but an explanation would be helpful. I think you have the arms right, but I don't think the legs quite work. Stand up and act out what he is doing in a mirror. I tried, and moving my feet away from the object like that feels very unnatural. I think he could keep the feet rooted and it would look better. Good work on making it so he looks like he is looking at the object, then looks ahead.
Ah the walk... this takes a while to animate with such a big character but it is worth it to put a large amount of time into it. I wouldn't say your walk is horrible, it's not bad for a 4 frame walk cycle. However, a 4 frame walk cycle will only ever be so good. You have the 4 most important frames for the walk cycle (two contacts and two passing), but the standard walk cycle that I have learned, and that I see most, is an 8 frame walk cycle. Look at this timeless reference from
Idleworm:
As you can see, you do not have any high point or recoil frames. If you add these, it will make your walk look immensely better and smoother. When you add the recoil frames then the character looks like he is actually making contact with the ground, they are key. Kudos on making two separate passing frames... most first walks I see the person tries to cheat and use the passing frame twice, it never looks good. Aside from all that, I think he is leaning too far forward for just a walk. Get up and watch yourself walk around, and you'll see that you only lean forward a little. Usually, the farther you are leaning forward the faster you are going, so in a full sprint the angle will be severe, with just a walk the angle will be slight.
Well this is all I can tell you. Hope some of it was useful. Good luck.
