The AN-2 has a radial piston engine, not a turboprop. It's reliable old school powerplant is the main reason why the bi-plane is still in widespread use, even with several air forces today. Especially in harsh, cold regions the AN-2 can still be operated fine and failures are easily fixable.

The 8 engines in front of the Screenoplane were used only for "take-off" and slow motion, they are located under the wings with nozzles that direct the flow. In real flight, the rear two engines were used. and that makes a lot of sense. When they're on, the plane basically behaves like a hovercraft, pretty clever!