So what I like about Demigod in contrast to DotA is:
1. Demigod has no Lasthits! I can't emphesise enough how great that is!
Lasthits switched the focus on dealing killing blows to the creeps rather than fighting versus the enemy heroes. Less action but focus on not loosing any money...
Dota was a great game, I would even compare it to chess in deepness of strategy and tactic.
But the lasthit mechanism would be like playing chess, while a random sound indicates that you have to press a button quicker than your enemy, otherwise one of your pawns vanishes.
2. Action!
Demigod is way more fast paced in terms of combat than DotA.
Much of this comes from #1, the lack of lasthits but this is a unique point in my opinion.
DotA is more like Hide and seek or a shy sniper camping in an FPS.
While Demigod feels more like WAR! It's very much comparable to a World of Warcraft Battleground where Death should be avoided but is no shame if you got some enemies with you 
3. Balancing.
While I woulnd't say Demigods balance is perfect, it's for sure compareable to DotAs balance.
The difference is: Dota is 80% about strategy before the match starts and only 20% actual gameplay.
That comes from the variety of abillities and the sheer number of characters. Balacing every hero against each other is not only hardly possible it isn't the aim of DotA.
It's all about counter picking, lategame vs earlygame, ranged vs melee etc.
E.g. Faceless Void from DotA is very weak early game and coun't compete really vs anyone 1v1.
But after ~lvl10 he becomes a killing machine and could wipe out the whole enemy team with lvl 20.
Demigod is here also much like World of Warcraft. Everyone is designed so he can compete in 1v1. Sure in WoW and in Demigod aswell there are certain twists, some heroes or builds that perform better vs specific enemies.
But it is miles away from DotAs Rock<Paper<Scissors system. And I like that!
4. Grafics and Zoom!
The grafic of Demigod isn't even comparable to WC3s aged engine. But damn it looks nice!
But even more important: The Zoom!
I played Dota recently and kinda got Claustrophobia.
It's like sitting on your heroes shoulder and looks awkward on larger screens.
DotA even forces the player to adapt to the lacking visuals and the little overview so you have to look on the minimap as much as you do on the actual game!
It's one of the social riddles of DotA that some people want to tell you that looking on to a little colored map is a "essential skill" of good players rather than a limitation of the engine.