Interesting reading.

Can Biped be used to model more complex games, such as Halo or Assassin's Creed, or is it targeted at 2D games like checkers or Motherload?

In [3] you mention that some researchers in the 70's started working on Datalog. Is this the same Datalog query language used in the Datomic database? 1

1 Datalog is in video #2 here: http://blog.fogus.me/2012/03/05/datomic/