Ever wonder why so many cartoons use simple designs, while most comics use realistic and very detailed art styles? Because what works as a still doesn't look very aesthetically pleasing in animated form, and this is a perfect example of that.
It's obvious you were trying to go for an anime style, but doing that as a solo animator is probably not the best idea since it sacrifices animation quality. Hell, it sacrifices the animation quality of PROFESSIONAL productions, just imagine the amount of effort it would require from one single dude. The one good example of an anime-styled project made by one dude I can think of took around 4 years to complete, and that was a short 5~ minute animation. That said, there WERE some nicely done moments in this, like the action scene with the archer and the girl, and the swordmanship scenes were generally decent (even if there were a few too many side smiles).
Since I don't know where else to fit this, I'll just include it here: The colors are too bright. There's too much contrast between them, so you should either lower their saturation or find color that work better with the character designs. The former would be easier, the latter would be preferable.
Let's move on to another area, sound direction. It is probably a good idea that you learn how to balance audio levels, The music is way too loud in places ("They're over there...makes ♪DANANANANANA DANANANANA DANANANANA♪" "What happened to keeping a low profile? I know, I♪DANANANANA DANANANANA DANANANANA♪"). I wish I could comment on the voice acting, but the music was too damn loud most of the time.
The writing was pretty good in the beginning, but then it became way too cliche'd as the video went on ("Your worst nightmare!" "You can't fire me, I quit!". And of course, "If you do thing, I'll do thing! "...AHAHAHA").
tl;dr: Simplify the character designs if you really are planning to turn this into a series. Learn to balance audio levels, and remember that moving lip flaps does not really count as animation (at least make them move their jaws).
And of course, sorry if I seem too harsh! I'd give you a 3, but Pico's comment on the 2 describe my general feelings on the video, but I also enjoyed it quite a bit, so I think a 2.5 is a rather fitting score.