Menu creation.

You can access the standard menus from the game itself within the map editor using OpenResurce (you can rearrange the buttons as you like and add your own). There, a portion of the object graphics is linked to different values and fields. You can explore it, although I'm not sure how much it will help.

In my opinion, the style isn't great, although it is beautiful: it's too similar to Dungeon. It's a matter of taste, but dark gothic and Heroes 5 don't really go together.