Hello, Chis!
I love the way these scenes look, they're full of lots of great colors and fine moods. I especially like the character, he (I think it's a he?) has a lot of charm.
However, he looks a little stiff. I think maybe you should try to relax his pose and attitude a little, make him look a little less tense.
I made an edit to try to show what I mean:

I kept the design the same, and he's the same size, but I made a bunch of cosmetic/pose tweaks.
-Dropped the shoulders down and brought the arms out some
-Unzipped the raincoat a little ('cause nobody goes around with it all the way up unless it's pouring) and made his neck visible
-Flared the raincoat out at the bottom and gave it a pocket, gave the kid a pair of shorts
-Rounded out the face and gave him a nose and ear
-Brought out the hood and gave it a bit more swoosh and shadow
I really love this character, it's simple, yet effective. I don't think you need to add many extra details to his design, keep it kind of plain and let the bright color and simplicity speak for themselves. I have a few minor issues with some of the terrain (like what NaCl said about the blocks), but it's in a WIP state and you'll probably iron them out on your own. I really hope you follow through with this, because explore-em-ups are my favorite kind of game.
(Edit:) Bonus edit on what I meant about the blocks.
