It's a pretty boring DotA clone with less variety, no last hits or lane control. My buddy from work bought it and let me play around with it. The problem with DotA is the community is terrible. The problem with Demigod is that they only take the casual aspects of DotA and left out all of the variety. The maps are boring and bland, line of vision is basically just a small circle around your hero.
There's only 8 heroes which is bad enough by itself but I could stand it if they were well balanced because at least they each have three "talent" trees they can use. They are not well balanced unfortunately and to add insult to injury about 3-4 of the heroes all play exactly like eachother.
The Demigod version of the "towers" take far too long to kill, resulting in long drawn out matches with little variety. It's far too easy for heroes to escape eachother. The ability to upgrade NPC's sounds nice on paper but it's one of those things that doesn't work out well in-game.
Performance is acceptable on a high end machine but sluggish and painful on low end boxes. The engine itself is no big accomplishment so the game feels like a rushed beta product as a result. Multiplayer uses some weird P2P system where if one person lags, you all do. For those who played DotA, it's like when someone got DC'd in-game and you all had to sit waiting or click the DC button.
Impulse itself had a few problems as well, though it's hard to tell if those were simply due to launch day issues or not. I like the idea of Impulse but the implementation is unproven in my mind so far, time will tell.
So basically it feels very rushed, bland and there is a distinct lack of variety. It CAN be fun but the feeling is fleeting and I can imagine running through all of the hero combinations in a few weeks at best. The game is not worth it's asking price in my opinion based on my play experience. There's just not enough meat on the bone.