I like your land shapes a lot! Especially the large central continent, it looks really interesting. But I must say, at the size you're drawing this, there's room for much more detail. It would be more useful (to someone who needs to know the heights) to see more levels. You could probably show every 500 meters or so. The steps are irregular too, now – 400, 500, 1400 and 1100 – which is quite confusing