Agharta: The Hollow Earth

Agharta: The Hollow Earth is an point and click adventure game set in 1926, where you play as a pilot who is asked to fly to the North Pole and find a scientist who was lost with his expedition to find the entrance to the Hollow Earth.
 PC

Developed by Aniware and originally released in Sweden as Agharta: Jordens Inre (the Depths of Earth) and later released as Hollow Earth (in Germany) and Agharta: Hollow Earth in English speaking countries.

Agharta is heavily influenced by 30's and 40's adventure and mystery comics, to the point that the game's cover is made to emulate the cover page for an comic book of that era.