The final meteorite revealed a Crystal Creature tormenting the far north inhabitants of Greenland. However, the World's Finest Team of Superman and Batman teamed up to overcome this foe, as the Dark Knight removed the Kryptonite present leaving the Man of Steel to transform the being into an inert form... squashing his plans to prove he was the mightiest of his kind.
Interestingly, during the first meeting of the Justice Society of America, Earth-Two's Superman and Batman were unable to attend. We know what Superman was during around the same period of time, in the winter of 1940 (Superman #7) when the Society's meeting had occured, as he traveled to a city terrorized by a fiendish scientist named Kotzoff. Kotzoff used a weapon to transform humans into reflected glass... similar to Glass-Man whom we considered earlier and similar to the reflective Crystal Creature who had changed Greenlanders into replicas of itself. However, the Man of Tomorrow made quick work of Kotzoff and his corrupt allies in the government.
So now that the Appellaxian meteorites and their spawn have been dealt with, and the menaces of Earth-Two have been dispatched, how would the first day at the JLA and JSA conclude?