Andrew Watson, who has a small part as Benjamin's sergeant (the one who says "you, move that way") is an actual sergeant in the military.
Darrell Wilson - who plays one of the soldiers - previously worked in World War I reenactments. He was able to act as an on-set consultant over the correct way the uniforms should be worn.
Director Thomas Pollock cameos as one of the soldiers Otto sees from afar in the woods.
Benjamin - who says he's eighteen - says he was expecting Otto to be older. Bobby Calloway is two years older than Andrew McNeill.
An early script idea had Otto hallucinating that he was seeing a flaming zeppelin crashing to the ground. Andrew McNeill realized that would look too weird and didn't include it.