Ok, here's my honest and fair shot:
I'll start by saying if you've ever played DoTA, you'll have a rough idea of what to expect. Generally it's an rts with all the same basic requirements. The differences are that you only control one "unit". This unit is like a hero from similar games, far more powerful than normal units and with several abilities himself/herself. If you've ever played diablo, your hero and his advancement is almost exactly that same as it was in Diablo.
Now imagine an rts where two prebuilt bases constantly pump units at each other. You're a super-commander with special abilities and like any normal rts you want to trash the enemy base. Of course you'll be hindered by enemy super commanders who want to do the same.
The end result is a fun e-sports style arena fest with a lot of fun rpg and rts elements. For example , you can upgrade units, buildings, ect, much like rts games through the citadel window. On the other hand, you can buy items that increase the strength of your demigod (more health, more mana, more movement speed, more damage, chance to aoe, chance to stun, ect) much like an rpg.
I think it's fun, but personally I like this type of gameplay. It combines some of the best parts of popular generes into something unique and puts it into the oh-so-popular PvP setting.
I once heard this genre described as "an fps turned into an rts", which sums it up pretty well. You're still trying to gun down other players and you'll hear the usual "I win" fanfare like "Godlike" when you kill someone else, but there will also be the usual rts elements such as resources and bases involved. While hardly new ones, Demigod does have plenty of nice features and is actually very balanced right off the bat.
There are a ton of improvements that can be made as the community has already expressed (to death), but that can pretty much be said of any game and I feel it's more of a path to take with mods/updates/expansions. There are a few tiny things many of wish were added, some of it already in the works, like clan support, a better chat system, so on, but none of it really detracts from playing the game itself.
If you don't like the round by round kill fest style of fps games, nor the rpg element of character building, nor the rts element of base destruction, this game isn't for you. Since you're at least somewhat interested, I'd say you probably like one or more of these qualities. The production of the game is top notch, even if the single player isn't exactly the most epic of tales.
A good example would be to say it's like Team Fortress, you don't play it because you want an epic story. You play it because you want some quick team based PvP fun and that's what keeps you and many others coming back day after day. It's pretty much the same for Demigod. While far from being the "perfect" game, it's a good one that I honestly believe is fun to play if you put aside the issues it's been having recently.
It's a unique genre that hasn't seen much light since DoTA or HoSK, and it's my honest hope it becomes a full fledged genre or at the very least a subtype.
There.. I apologize , it's hard to be 100% unbiased. If you have any specific questions, myself and the community would love to answer them.