What are you looking for input on? These all seem to vary quite a bit so it's hard to judge them all to see what you are going for. It might be a good idea to narrow it down a bit.
For the first one, are the weapons attached to the creature? If so they don't seem to be positioned in the most functional way. The hammer/mallet seems like it could only be used for upper cuts, and I think you'd want the business end of the axe facing outward. It's an interesting creature. I think it would look better if you refined the detail and maybe considered his weight. His legs don't look like they could support his body, and it's hard to tell if he's standing or leaping being you cut them off.
wow, these are all really beautiful and well done ;D
I especially like the ones with the skeleton black/white lines, the roughness there is quite cool!
Ok, critique is pretty hard on these, one thing I notice thought that you almost don't work with background/foreground or perspective.. your focus seems to be a bit weak too.. also I also have the feeling that you are not exactly sure how to convey a message in a picture..
I recommend you these threads because I could not explain it better: http://www.conceptart.org/forums/showthread.php?t=71673
(this could be useful for the troll picture which is pretty flat and lacks dynamic, also nice for zombie in landscape and dwarf)
http://www.conceptart.org/forums/showthread.php?t=37222 (I like how that guy built the dynamic in the figure - compared to monkey king your dwarf looks static, which could be improved by taking the sword in the foreground and having a focus with your saturation, darkness and contrast)
Troll picture is unbalanced, it tilts to the right because of high darkness and saturation there.
I don't know much about concept art, from an illustrative point thought I wonder why the troll is there and what your focus on the picture is.
You could pack a lot more information about troll and his background in this picture.
landscape has interesting colors, i like that you are radical like that ;D
You know that the pink clouds seem to be closer than the yellow field because of their higher saturation?
portrait- nice I think you are good enough to be even more daring with unusual colors in his face (after the colorful pictures before this looks a bit dull)
skullguy in field- I really like this and I hope it's unfinished
Here the maximum amount of details is on the right and unbalances the picture.
Putting something to the left (for example a village in the distance, so that it looks like the zombie tries to grab it symbolically?) gives the pic more balance and maybe more meaning.
Dwarf- see the monkey king picture
Logo? No crit from me
Zombie- nice frame, the messy structure of the picture lets the frame appear a bit empty. (I would recommend an extremely faint handwritten sentence or signature or anything on the frame.. or a very subtle paper structure- but that's maybe just personal taste, I can't help you much more than saying: it doesn't look exactly right)
Like I said, i like those pictures very much and I hope you keep up your good work, it would be awesome if I could see what you will do in one year.
thank you both for the crits. I do tend to leave the backgrounds empty mostly because I dont like environmental designing because im not good at it. Which is something I should work on instead of not. The links posted are very informative, I'll check them out in detail soon. As for the zombie one with the white flame on its head. I had toyed with the idea of putting something in the hills so it looks like he is reaching towards something. The piece is titles "Home Sick" and I wanted to put a graveyard in there but I could not get it to sit correctly on the hill and proportionilty in order to make it visible it would need to be shown bigger then it should. Something else I need to work on.