Secret Files: Tunguska (German: Geheimakte Tunguska) is a 2006 graphic adventure video game developed by German studios Fusionsphere Systems and Animation Arts and published by Deep Silver for Microsoft Windows, Nintendo DS, Wii, iOS, Android, Wii U and Nintendo Switch.

One night, Nina's father, Vladimir Kalenkov, in his office in a museum in Berlin, is suddenly attacked by a figure in black robes who seemingly possesses psychic powers.

They also found a fragment made from an unknown material and Vladimir, in his "Kalenkov Report", proved that the object was from extraterrestrial origin, but the results were kept hidden by higher up and they were forbidden to continue any further.

Despite that, Vladimir organized another expedition in 1977 with Cuban Manuel Perez and Ken Morangie (an Irish biologist), to search for more fragments but they were intercepted.

Oleg offers to take Nina by his plane to Moscow, while Max stays behind in case Vladimir appears, and she eventually manages to get on board the train.

Max also discovers a medical report about patients with severe mental and behavioral anomalies from unknown causes, and that it was quite common in the region.

One of them was Manuel Perez, who returned from the expedition with Vladimir, having the same psychological anomalies and after having been treated in the hospital for 30 years, he was recently transferred to Cuba at the request of a Dr. Nicole Charlesroi.

Max is left in Ireland to search for Ken Morangie and Nina visits the mental institution in Cuba where Manuel Perez was transferred.

After she finds a strange metal artifact resembling the Dropa stones, he knocks her unconscious and takes her to a research station in Antarctica where he meets with Sergei and Charlesroi.

Nina and Max then manage to create a chemical reaction in the facility causing an explosion, which utterly destroys it as they flee and a lengthy and humorous ending cutscene follows, presenting scenes as if all of it was a film-making project.

Tunguska was first released on personal computers in 2006 and was ported to smartphones and as many as four Nintendo gaming systems in the years that followed.

The first ports were to seventh-generation Nintendo platforms, the Wii and DS, which Deep Silver announced the following year, stating: We chose to do it for a couple of reasons.