Loved the idea, love the graphics, love the presentation, hate the level design...
WAY too linear. Obviously linear, too, unlike Half-Life or some other well-designed shooters. More than anything, it reminded me of No One Lives Forever, where there was almost always a single path that you HAD to conform to. Still, XIII has the potential to be a great game, especially if the story lives up to its full potential.
And it was unbelievably cool the first time I threw a glass shard into some poor sap's eye.