DOTA has over 90 heroes, and Demigod has only 8 heroes or demigods as they are called. Split into Assassins and Generals, the assassins are mostly pvp focused on taking out the other teams demigods whilst the Generals can summon minions to fight by their side. This makes for some interesting strategy as alot of items in the shops boost minion stats and are pretty worthless for assassins.
I think the level cap is 20, and the way there leads through pretty basic skilltrees and a whole lot of choices on where to spend your cash. You can either buy items for your demigod or you can upgrade the citadel which makes your teams reinforces stronger, their towers stronger, makes the team generate gold or experience faster and so on.
There are also Favour points to be gained after each match of online play, the system is broken right now, but it seems promising. You can unlock items for you accumulated favour points which is then unlocked forever... in theory.
Graphics are sharp, models are very cool the spell effects are fantastic.
Sound is well done, I wish you could hear more sound of the AI controlled smaller units fighting. Music is bombastic.
Gameplay is very responsive, camera is great.
At launch the game had alot of trouble getting multiplayer working online, they seems to have ironed out a few issues by now, but still the Peer 2 Peer system they are using keep people behind firewalls from playing stable games.
Summary:
Gameplay: 4/5
Graphics: 5/5
Sound: 4/5
Replayability: 3/5
So, is the game fun? Yes, it is very awesome if you are into multiplayer, the singleplayer is NOT worth it on the other hand.