Not bad for a first attempt. I’m not sure how much of the uneven pace was due to the FPS lagging in the UI, or due to YT playback since I’m in the middle of rendering stuff and that causes hitches in video plays. However, there seems to be too much difference in momentary velocity through the cycle, the forward pace speeds up and slows down too much, see if you can make that more even.
Two major crits:
Weight transfer is almost non-existent. When walking, it is a basically a controlled fall forward that is “caught” by the foot being placed ahead of the body, so weight is always being transferred from foot to foot. Maintaining balance, and our general bipedal anatomy, requires that as this happens the Center Of Gravity (COG) of the body shifts from right to left and back again. This also generates a shift and swing of the pelvic area, which is more pronounced in women and gives them their appealing “sashay.” Take a look at reference material (Eadward Muybridge’s nude motion studies are a very good source for this) and observe people walking and you’ll begin to notice how the weight shifts with each portion of the cycle.
No syncopation. In music, that term means beats that do not fall together, and are slightly “off beat” from the formal time measure. In human motion, it means that the various components of the cycle, the leg swings, the arm swings, the hip rotations and weight shifts, all fall at slightly different times in order to produce a “flowing” look. Part of this is maintaining that COG properly, but also just plain physical inertia. For example, after the arms swing back, they won’t swing forward at exactly the same time as the same-side leg swings back, because the weight of the arm loosely swung tends to make it lag just bit. This also means that the arm moves a bit slower at the peak of the backswing than at the middle of the sweep forward. The motions are non-linear.
Looking at your Dope Sheet, all the keyframes are lined up on the same frames, and this defeats the idea of syncopation. It’s OK to block the basic timing this way, but to finesse the motion, you’ll need to break up that alignment of keys to allow for more natural pacing. Learning that pacing is a matter of study, observation & practice, and you have a good start.
HINT: Learn to make OpenGL renderings from the UI. You can render to an image sequence and use the VSE to make a quickie video file, or render direct to a movie format, but it’s quite fast, and helps a great deal when evaluating timing because it’s at true full FPS. For working in the UI, consider making yourself a low-poly animation proxy, a model that is so simple it will always allow playback of animation at full speed in the UI. It can be bound to the same armature as your main model, and kept on a separate layer until needed. This is particularly important when working with more complex character models.