Alright, I have just finished the campaign and here are my thoughts and feedback, I'll comment generally on the campaign and then each mission:
General:
Terrain (10/10):
The terrain was so damn amazing, it's been a long time since I have seen something so beautiful. Nowdays, most campaigns I see and play just don't use the blizzard cliffs and terrains and focus mainly on the main path and some dead ends on the way but you made the terrain look real, the areas were so well done, many paths, narrow passages, wide areas, trees, ice thingies, just... amazing!
Gameplay (5,5/10)
About the gameplay, I enjoyed the game to some extent, but I'll describe more in the missions down bellow.
Customization (3/10):
We get to play standart RoC humans with the custom unit Dwarf car, which in ok I suppose (and really powerful

) but maybe you could use more custom units for dwarfs, not just priests and footmen. There are Falric and Arthas as custom heroes, which is not really that much, maybe Baelgun could be more original as the basic mountain king hero is just... basic. It wasn't bad but it was just not that hard to play as he doesn't really have hard-to-use spells.
Cinematics and texts (1/10):
Like... what the hell, man? I had to focus hard on the text and still I didn't understand half of it. The cinematic texts were not really understandable, the spell and unit texts (for the custom ones) were somewhat understandable but full of mistakes and just... comon. If you need help, I can help you rewrite it all because it needs it.
Missions:
First (7/10):
The frist mission was pretty straigh forward - go and find Arthas. I liked how you made it so that we really have to search and not just point click on a circle and wait. The area was beautiful, the terrain realisticly narrow and wild. I disliked just one thing - we get to have gold and wood to buy mercenaries, but we also find troops along the way. The moment I reached the first merc camp and I saw the mercs I though that there might be something better in the next one but by that time I had food population over the limit and about 30 units (which made it impossible to fight in some areas effectivly). I recommend you reduce the amount of units we receive and deal with the food cap.
Second (7/10):
This mission was nice as well, a bit similar with the human campaign with the dwarven base, but sure, why not. I liked how you made the terrain again so well woven and added some mobs around the map. What was bad, however, was finding the gold mine. I thought that the base, that you are supposed to destroy and overtake, is the final one and so I walked around not knowing where the gold mine could be. I also didn't really like how you used the same model of nerubian buildings for everything. That felt just too plain. I recommend you make the first base smaller, so it's obvious that it's the target of attack and that you add some custom nerubian models.
Third (5/10):
Azjol-Nerub is really well built. I liked how you even leave and reenter it. The units are pretty basic as well, some mechanisms and teleports and traps - it was nice, I really loved the water trap. But what really wasn't nice were the moving platforms. They are SO ANNYOING to deal with. I also didn't really understand how the humans go stuck in there, that wasn't explained. I disliked that you get to control the big monsters you kill on the way. They are just too powerful and again, not really explained how they did it. Again, bad moving through narrow passages but I suppose I was just overprotective with my units. Lastly, the bosses were nice, though the last one, even with full army, was too much. Spell immunity is a bi- ehm.. female dog... I recommend you remove the rebirth runes.
Fourth (4/10):
This mission was too plain. We have a base again and now we have only one straigh path through a HUGE undead base in the way to reach the circle, while Arthas is buffed as hell and kills his units too quickly. I didn't enjoy this mission because nothing felt right. I recommend you look more into it and change it a bit. I liked though the different ending cinematics.
So there it is, the final rating is 3/5.
Honestly, it was great to play it, it was fun, but it was also a pain in the butt. If you correct all the wrong grammar and make the cinematics less... childish and more serious, the rating would be better.
If you need help with the texts, just ask, I'll gladly help you.