Much effort, not much result
I like some parts but most of the parts just don't like
You can see that this took a long time to make. But you can also see that you aren't able to turn this all effort in a nice looking result. First of all, I don't like the style. I like sketchy style though. But this is rushed semi-sketch style. I know that the style you used takes more time than just collour it, And I even noticed some nice shadow work, but most of the time it is not done with the attention needed. The brush u used was a little bit to big sometimes. Animation can be very cool if you don't know how it is made. You recognice every brushstroke in your work.
Another thing. You said that you know that "there are a few mistakes with movements and everything". I agree, only there aren't a few mistakes, almost the whole movie is made out of mistakes. Walkcycles that doesn't walk the way they should. (even though I think you did take some time to study the way animals walk.) Your lines aren't smooth and mostly because of that the movements are not smooth, and therefore look crappy. I don't know if you used a tablet, If you didn't, you should, because that makes your lines a lot more on the right place most of the times. I like frame by frame work, some FbF animation in this movie wasn't to bad, but mainly because the lines were wobbly, it just didn't look right.
Another thing (again). The timing. Animation where you use voices is very difficult to make it sound right. You're timing is a little bit strange. Some parts look okay. But most of the time you wait to long. Especially in the conversations, and change in the moods of the characters. You should try to expiriment a little bit more with the timing, and if you think: yeah, that's right, you must keep it that way. Critic frome people around the corner are always helpfull. Timing is one of the most important things of animation. I know this, because I make the same mistakes as you do. Animation with voice-actors isn't a thing for me (yet). Lip sync was okay, but could have been better. The voice-actors could do a little more emotion in there voice. Oh and always add some backgroundsound, that would help. Anothere animation rule: if you change cameraview, don't make the character in first shot as big as the one in the second shot. Some camera angles you used where very good though.
The last thing. This is just a thing that I don't like about it, I know a lot of people around NG do like this sort of stuff. But I don't like the characters. I know you have seen the Lion King, And I know you like it. I also know you will say, that this is totally different, but I think this is just a Lion King rip off. I know that there are giant Cults around these things who like to make fan-art and create 'own' lions, but I don't see the creativity in that sort of stuff.
I don't want to discourage you, on the contrary. I can see you are able to put much effort in a animation, more than the avarage animator on newgrounds. But you need some feed-back on your work to improve it I think. A big production lik this would be much better than.
Good luck with it!