Sacrifice was critically acclaimed at release, and with good reason: it succeeded in merging 3rd person combat, RPG elements, real time strategy, and a huge, non-linear storyline.
This complexity comes at a cost however: while controlling hundreds of units is easy as pie in most RTS games, the lack of a top down camera makes it noticeably harder to adequately control all your units on the battlefield, with many battles degenerating into free for all brawls, as opposed to the micromanaging antiques of Warcraft.
Still, a stunning game, which you will definitely enjoy once you manage to fight your way through the first couple of stages.