Hmm, not that I know much about art, but it feels to me like your colouring is sort of flat. Like, the 6th one from the top with the guy holding a spear and looking over to the left, his skin seems like theres only two colour. One for the skin, and one for the extreme shadow. I'd like to see more colours in between, and maybe highlights on the face as well.
You won't get anywhere in the art industry by just hoping people will notice you. You need to build yourself a network and get out there and get yourself noticed. Go to real locations and talk about job opportunities in various fields, including things like comic books, animated films, concept art for various industries, illustrations for anything you can find really, cartoonist, etc. You have the skill and both the imagination and technical skill, don't fool yourself into thinking youre not up to par, no one is at first. You get better by working on projects. Start your own indie project, make a good website, talk to people, find connections. Don't come here and ask for advice, you're past the point of having people on forums critique your work. You know what you need to improve and how to build up your portfolio. Why would you even ask whether you need environments or larger pieces? Of course you do... You show no variety in your style, technique, or characters. Might as well have shown only 2 of those and I would have still gotten the same impression as I would with seeing all. You need to show you can do more than just character design, that's how you get noticed. Hell, if you're good at drawing or painting show that, just show something that represents you as an artist, not as a specific job seeker. Just broaden your portfolio and shove it in people's faces and make sure they know who you are. Build a fanbase if you can on Tumblr and Deviantart or something like that if you can.