I would say this is something like the Cohen Brothers' take on the classic western, but I guess they've already done that. The humor is similar - contemplative but frequently absurd - and it has the rambling nature of O, Brother, Where Art Thou without directly mirroring (as far as I could tell) any classic epic poems. 
 I do like this tweaking of the genre and deWitt has created a couple of interesting characters here. Eli Sisters, the narrator, is somebody that could stick with you for a while.