I hate to say it but all of your stuff seems pretty much the same to me.
The only critique I could give is try different things. Try drawing things from life, try different mediums, look at stuff you wouldn't usually look at - that kind of thing.
You might not have any interest in drawing things realistically yourself but through that kind of practice you can take back all kinds of skills and ideas to what you do want to do. The wider the range of things you learn the more you will be able to express the characters you want with different backgrounds, in different poses, in different lighting, in different situations and doing things in different ways.
I'm fairly sure that no succesful artist starts out just drawing repetitive characters in repetitive poses. As far as I know even people who succeed in very specialised or cartoony styles have some background or practice involving traditional skills.