Scott Adkins was rehabilitating his knee from an injury and taking a break from making action films, hence the lack of big stunts and fights on his part (which was not what the project was about anyway).
Filmed in native 3D.
Willhelm scream at approximately 37:55.
This film marks the second reunion of Scott Adkins and Dolph Lundgren after Expendables 2 and Universal Soldier.