Despite what mcmasters said about constructive criticism, I'm going to try offering some, haha. I will say that I certainly don't expect you to make these sort of changes overnight, but I'm hoping in the long run you can improve yourself.
I'm enjoying the story so far, though it's hard to comment on it much since it's not very far along. I think the artwork could use some more practice. You seem to have the general anatomy down, but need more practice with drawing different poses. Like mcmasters said, it's very stiff.
Here's some things I'd suggest you should keep in mind and practice:
1. In most panels, the shoulders and the head are perpendicular. Even in casual conversation, the shoulders and head move, because they're often used for expression. Don't forget that people shrug, tilt their heads, etc. and quite often won't fall into this flat position. Their movements can help add to their personality.
2. Most panels are really zoomed out. During the fight with the monster, we don't really need to see the horizon in most of those panels. Zooming in on more of the action would be good.
I'd like to note that what you've done in the first and last panels on page 12
looks good. But I think the other panels on that page could have been done differently.
Doing some extra sketches of dynamic poses and angles outside of the comic work will help you improve faster. I'd suggest looking up some stock poses and practice drawing those. SenshiStock on DeviantArt is one of my favorites, but it's mostly female models.
Be sure to have fun when you're doing them, of course; don't do it only to improve, because then it becomes a chore.
Those are my thoughts. Feel free to think I'm completely wrong through, and do whatever you want. I'm new to webcomics myself so I could be completely off-base with #2.
And to reiterate what I said before, I certainly don't expect you to make any sort of drastic changes to your art style overnight based on what I think. Be sure to use whatever works for you and feel free to make any changes you think necessary slowly. I'm just some schmuck on the internet anyway.