As some one who played Reign of Chaos DotA for 4 years, and Dota Allstars on the Frozen Throne for 2 years, this game is similar, yet completely different.
In Allstars, it's really not that hard to win 4v5 or 3v4, whereas in RoC Dota it was near impossible.
In Demigod it can be a little of both, depending on when the player leaves the game, if some one leaves before level 4 or at the start of the game in Demigod, it's basically game over. It makes no sense for people to say you suck at a game when your undermanned, your at a disadvantage, and at the same time, it's not embarassing for a team who has the additonal player to lose. It all depends on the skill level of other players, for example, when I play with my friends, I think i've lost once, where as when i play with random pubs in this game, I almost always lose because they are so bad, you can't carry in Demigod as much as you can in DotA, and I think that's a godo thing.
Demigod does a good job of mixing individual play with teamwork.