there are gods, giants, elves, dwarves and trolls;
the chief god, Odin, converses with other characters and initiates major events;
the jotun or "giant" race are not all uncomely or of gigantic stature;
Jotunheim is oversea north of Midgard.
The fact that Jotunheim is not part of Midgard/Earth but can be reached by sea entails that the sea voyage to Giant Land is the mythical equivalent of a space journey even though the direction is north, not up. Symbolically and appropriately, our thinking rotates through ninety degrees when our attention turns from mythological reconstruction to scientific extrapolation. Anderson incorporates both reconstruction and extrapolation into diverse works of imaginative fiction.
The voyage across the sea that encircles and defines Midgard is made in The Broken Sword and Anderson's The Demon Of Scattery is a tale told during that voyage. Thus, mythical cosmography closely connects these three novels. Anderson writes in the Afterword to War Of The Gods:
"With the cosmic framework I have taken a still freer hand. After all, we have lost much. Lines here and there hint fleetingly at what must once have loomed high..." (pp. 302-303)
Chapter I summarises or alludes to several myths. Thus:
"...jotuns remembered how Odin and his brothers slew Ymir their forebear." (p. 10)
This refers to the Norse creation myth because the brothers made the earth and sky from Ymir's body. Before that, there was only a Chasm or Void where northern cold and southern heat condensed to form life, starting with Ymir. (The account first of a void, then of interaction between opposites generating life, amounts to a philosophically sophisticated creation myth. Arbitrary elements, like a primeval cow to feed Ymir, had to be added to keep the story going.)
The retold myths include the story of Mimir's head which is consulted in Anderson's Operation Luna (see here).
War Of The Gods retells and reinterprets a heroic myth whereas The Broken Sword goes further by presenting a sequel to a story told in an Eddaic poem and a saga. Anderson historically progresses the mythology by adding "...new gods..." to "...this game between Aesir and Jotuns..." (p. 196)
One new god won as we, living later, know.