If you take it as a stand-alone anime, it's watchable. Might pick up later (and probably will), but it's decent.
If you take it as an adaptation of the game, it's a crime. By ep3 they've already deviated quite a bit from the excellent plot of the game (certain characters show up earlier, certain characters don't die, certain characters die earlier, etc...), and the characterizations of two of the important characters changes quite a bit. Allen seems far more annoying and Shion is a far weaker protagonist.
I'll keep watching to see where they go with it, but it's not high on my recommendation list, as much as I love KOS-MOS. (And I do so love KOS-MOS <3).
What I would recommend is Jinki: Extend, Starship Operators, My Hime, and Sokyuu no Fafner (completed within the past couple weeks).