The boy's left arm is very skinny, try to work it better(put more muscle in it), and also, try to put the boy's body straight, it looks like that he's falling to the side XD The colors and the shades are also very nice. The head and the face are very nice, like the girl and the....animal? XD The boat: You can work better on the boat's name, try to draw it better, you can take some ideias from actual boats or even from pirate's ships. Try looking for pictures of "Pirates of the Caribbean" and vikings ships, its a great help I hope I could help
Blizzmaster made the major points that I would point out, but I'll had a few comments myself.
Overall it's a pretty cool piece. The background is superb.
I can tell you're giving Ezreal more of a 3D approach, but something still feels flat. I think its his shirt. I'm not sure if I believe the shading perfectly. His fist looks like he's holding a bag or something, but they are really tight and don't really seem to wrap around the bag strap. Miss Fortune might have wider hips too.
But yeah, Blizz hit the most important areas to improve one.
Overall, this is a really cool piece though, and your hard work really shows through in all the careful detail. Great job!!!
I'm no expert on Yordle anatomy or anything, but I think Teemo is a little misshapen if you were going for accuracy. That, or he just needs some more detail.
Also, Ezreal's right forearm (with the gauntlet) is really thin, especially if he's wearing a gauntlet on top of his natural arm. The hand part of it looks pretty good, but the detail on the forearm just seems flat, almost like a tattoo instead of something he's wearing on his arm.