Welcome to the forum metsejadur! I was impressed by your drawing process (unfortunately the screens didn't made it into the forum), you understand the program you're using and the rules quite well, just lack some practice which can be earned daily by working on the next drawings
About that one:
I'll use my version as a comparison, which isn't fair in any way of course, but it shows you some of the key elements of the heroes2 style which is quite hard to accomplish.
1.
PERSPECTIVE. Try to draw the buildings or any other adventure map objects from the front, not from above. So any stairs will be flatter, side walls shorter etc. You did well here!
2.
COLORS. The game uses special color pallete, not every color like you can use in the program. If you're reading this
Orzie, please provide
metsejadur with the whole pallete
So anyway, the result is that your work will look a bit different and can lack some colors, especially some exotic, vivid ones.
3.
LIGHT. The light always is coming from the right side and the shadow is on the left. You can clearly see this on my version of the skull, whish is darker on the side which doesn't recieve the light. It also makes it look like it's 3d, like it has the depth. Yours is just flat. For example your stairs look like they're in front of the mountain, not surrounded by it like on my piece. Add more shadows to the rocks and everywhere where light from the right couldn't get in real life. Look at the rocks by the skull. Right side is bright and left one is darker.
4.
TECHNIQUE. Use some blending, so not only a pencil tool, use brush too. Mine has some edges but not every one is very sharp. Just look at my skull's teeth.
5.
DETAIL. Try to give some thought into every part of the piece (drawing). Every part of the rock should have some details, shadow, some moss, in buildings it would be single bricks etc. Your right part of the rocks next to the stairs just has some black lines across it. Every part of the drawing is very important, focus on these too!
6.
PROCESS. Try not to draw on a flat background. It would be a lot better if you would always draw on dirt/grass next to the original heroes 2 object so you can compare it constantly. It would be best if you could just open heroes 2 editor and made a template for your drawing, place the object you would like to compare it with by hand :p I've made myself one for that drawing (it's on my thread), and so did
Orzie to show me how the arena fits on every terrain:
That's all, good job! I'm waiting for the next ones, with the use of my tips!