A real honest critique?
The story is really weak. You spend too much time drawing up the fight scenes, not enough time elaborating and developing characters. You have to make the reader feel for the character by getting to know them not because hes just kicking ass for the sake of kicking ass. Aslo what ibra87 said follows what I said. You barely get to know your first character before you are jumping in and adding an additional character. Not that having two characters make a story weak, but you hadn't yet related the main character to the audience yet and were introducing another character than the main character zero doesnt know either. One really big thing that I personally feel is a negative is the character designs. To be honest they come off naruto/ninja-esque with some feel from other other animes. They are very repetitive and bland as with most fan-style manga. Spend more time developing personalities through clothing that matches the atmosphere and environment (think ninja belongs in old school japan. soldier belongs on battlefield or cityscape) and less time on what you think looks pretty or cool.
ok all the bad stuff out of the way, now for the god stuff.
I really like your dedication to your project, it shows that you put a lot of effort into it. Your linework shows that you have a decent idea at what you are doing. Although you could benefit from figure drawing classes, you have the faces as well as actions lines down pretty well. The mixture of hatch lines bring alot of interest to the individual pages. You do have a mixture of compositions which helps the flow and variety of the pages. And some of the angles mixed with the linework offer dynamic panels.
Overall I commend you for your effort. Keeping in mind that the art world is a brutal, honest, and highly competitive world; I would recommend taking anatomy, figure drawing, and several literature classes. You have a lot of good things going for you but I think you have potential for improvement and that you should focus less on the comic until you can strengthen your skills as an artist. (think that football players, even if they want to play the game in a league, still need to spend lots and lots of time in practice before they perform on the field).
I hope I didnt come across as rude, I was just trying to help you out and be as constructive as possible, trying to show your areas of weakness so that you can improve upon them for future projects.