The demos from the book are incredibly lame -- hardly more than "hello world". I checked out the linked game engines, and of them the only compelling option se

The demos from the book are incredibly lame -- hardly more than "hello world". I checked out the linked game engines, and of them the only compelling option seems to be ImpactJS (Turbulenz is hard to tell since the website linked is user-targeted). That said, ImpactJS seems to be non-free ($99). (Not complaining, $99 is a small price to pay for a good library with documentation.)