Your latest picture has quite a lot of color going for it, but the proportions, like X said, need some work. For example, the red-headed character (I want to assume is Simon, but he's wearing an outfit similar to Hector?) has a head that is far too big for his body, and it is shaped to the point where it doesn't even seem to actually belong on that neck.
On top of that, his arm in the background holding the flower doesn't seem to be attached to the body. I'd suggest moving it somewhat downward, making the shoulder appear closer to his torso, since right now his shoulder is very far off from his body. The arms of the character could also be lengthened, since they seem rather short at the moment.
This one is just me, so it's not necessarily a needed fix, but the woman in the foreground has a bit of a man-face goin' on, to the point where (in my opinion), she resembles the Simon-Hector character. I understand if you were intending on going for a masculine woman (I don't know if you were), but perhaps try adding a few feminine qualities to the face while still keeping masculine qualities and you can possibly get what I think you were going for (of course, as you are mimicking the Kojima style, every character has feminine qualities. These must be more apparent on females, in a sense).
Your backgrounds, on the other hand, are nice. I very much enjoy how the moon in the background looks, giving off a very awesome gothic vibe. I also like how the tower kind of blends with the background, doing this sort of fade-in, where the part underneath the roof appears sort of invisible, and it becomes more visible as it moves downward.
All in all, you are definitely on the right track. With a few fixes and some more practice, you could definitely make it look top-notch.