Just finished the campaign, quite fun overall. Some comments
- Interesting artifacts and upgrades a strong plus for me, though a limited few that is quite meh. Pandaren amulet comes to mind, as it shares a cooldown with mana burn and summon murloc artifacts, both of which are much more useful than getting drunk. The flower spell book is also not very useful I feel, if only u can make the inner fire autocast work it would be better, but the other spells not as useful as auto attacks.
- I like the bonus stats on level up system, but it probably needs a rework, as choosing dmg is waaaaay better than the rest (except maybe female death knight? more on her later)
- Heroes rank from favourite to least
* Reaper: Love everything about this hero.
* Goddess of death: Splash autoattack is damn OP, love it, charm and summons are ok to carry early game, aoe spells only useful in her final appearance but damn its good.
* Ratman: The Terminator, single target and autoattack so good I almost never use the aoe stun. Maybe lower his attack speed? Reincarnation useful, but doesn't really fit in thematically.
* Ice elemental: Not much use for starfall, mob size rarely big enough to justify its use. Built him into an auto attacker instead.
* Lizardman: Nothing much to say about him, except that polymorph feels kind of weird in his skill set, but effectively nullifies spellcasters, duration probably too long.
* Pandaren: Drunken haze falls off pretty hard, stopped using it actively in the 3rd map, though i guess its there for thematic reasons. Disappointed that he only has evasion instead of drunken brawler. Chain heal is good.
* Pit lord: Nothing much to comment, does his role well as a tank. Guess he has a high strength gain? Didn't really realize until I'm writing this review. On a side note, he has a face that probably not even his mom would love XD.
* His bear/wife: Too much spell casting for an agility hero, i would have put her on a lower tier than the death knight if not for the fast mana drain. In fact, I would suggesting giving the death knight a fast mana drain as well. And could you fix her portrait during cinematics? She has a male demon hunter in the intro cinematics for the last scenario, and a male death knight face in the final cinematics.
* Female death knight: Too dependent on the mana drain. Probably the only hero where taking the non-dmg bonus on level up is more preferable as most of the time is spent sucking mana from druids. High mana cost single target stun is questionable as you would want to use it on Illidan, but he has an insane number of images, so better off sucking mana/summoning. Mana drain is useful in cancelling images, but again there are simply too many. More on that particular map later. Please fix her portrait as well, uses a male death knight.
- High Death: Shooter rats too OP if left unchecked, I unsummoned the crypt and temple right from the beginning as I don't need any units from those.
- Scenarios:
* I am biased towards curb stomping enemy bases with a pair of OP hero in the high death chapters, though mount hyjal could do with bigger enemy bases and harder boss fights.
* I like the goddess of death's final map but kind of rng dependent. Had to restart once cos she got targeted by spells too often, had to run back to fountain too often, thus allowing enemy to snowball (I had close to 10 of those light golems charging down the lane at that point).
* Map with green dragon roost: Theres this area with 6 ancient protector and a hero shrine, destroying that area triggers the hardest fight where multiple Elder Treants comes charging at the same time. If unprepared or without an army for that fight, its basically a death sentence. I think their entangle lasts too long, and if the death knight, or worse, kelthuzard get entangled amidst the army of big and small treants, its almost gg as your only healer is kelthuzard, and he cant heal himself. Also, please make the green dragon immune to charm.
* Death knight solo map is the worst as you get the weakest hero against a difficult opponent, with only two artifacts to support her. I cant think of any other strategy other than trying to tank with hero, summons and some melee units while praying your range rats takes out the chimaeras, Illidan and the rest of his army before they get annihilated (AI, especially the chimaeras, seem to love ignoring my frontline to target my rats). Had to reload multiple times just for that final battle. Illidan respawns too quickly, several times I defeated him outside his base but when i rush to his base immediately after, he has already respawned, not sure if that's intended.
* Final scenario: Not sure what's the point of having the mercenaries and having a quest dedicated to improving them when the mobs have charm, and your army wont be part of the boss fight? Very counter intuitive. Luckily I chose to invest in tomes rather than mercenaries. The mage mobs probably abit too strong. One of them has mana burn and fork lightning and probably enough mana cycle through those spells 2-3 times, while I guess the other mage mob has charm? And they look too similar to differentiate between who to prioritise stunning/killing. On the other hand the doom guard, a seemingly elite mob, is just a plain ol' grunt.
Pending
Regards and 
thanks 
. Looking forward for the next part, if there would be one
