One interesting feature about this, which you can see in the skeletal hovering demo machine, is that all the ducts are driven from a central source. Since air pressure is additive, that source could be multiple engines dumping into a single manifold before driving all the ducts equally by default. All the ducts need to do is swivel to direct the air.

Compare this to ships like the V22 which have an immensely complicated gear, shaft, and clutch arrangement to drive the props; this one also folds. Or against most multi rotors including the original Moller design where you need at least 8 engines or motors, two at each corner for safety, where you need a smart computer to balance the loads as motors fail.