The ending was lousy, yes, the world poorly realized, and the tonal shifts a bit too wild, but Andy Serkis owns the 3D CG character medium. I don't see how you could not be entertained by the quality of the voice and cutscene work.
And I don't remember it getting good reviews.
But yes, I know what you mean by unwarranted critical acclaim. I love GTA4 and RDR but the reviews for them are disgusting, especially from IGN. And that's not even counting games like Limbo.
Wasn't knocking there character/cutscene/voice over work.
It was incredible in Heavenly Sword. I just feel that years later somehow nothing improved and possibly got worse in terms of the actual game (was zero improvement over HS and yet the entire industry moved forward).
Honestly, I think my favorite part of Enslaved was seriously the music that plays in the XMB menu on the PS3.