This is blatantly a war time cartoon and does thus contain propaganda against the Japanese. Still, the cartoon is well done and does not preach anything. It mainly just tells a tale with the Japanese being the bad guys. The lettering of the title is a Japanese stylized. The knocking out of the guard was all in shadows and we don't actually see the blow fall.
Superman takes noticeable effort to try to break into the locked cockpit.
There is an effective jolting effect as he rams himself onto the door. Lois is very courageous, risking her life to send the message about the plane down to the ground. All in all, another well done cartoon with a nice bit of humor in the final scene.