The movie was shot by an Italian crew in Italian and Lambert (who speaks only French and English in real life and who spoke all of his lines in these languages) was dubbed by an Italian actor. This is the movie's original Italian audio track. The movie was then dubbed fully in English (Lambert dubbed himself for this version, so the English audio track has his voice) for foreign markets. This is the movie's English dubbed audio track.
The movie and the in-movie game are named after the Nirvana, a religious and philosophical concept used in religions of India (Hinduism, Buddhism, etc.) to describe the peace of mind, body and soul one reaches after all desires (the source of suffering) are extinguished. Many believe that this is accomplished through reincarnations, where every time you "come back" you get slightly more world-weary and closer to the Nirvana. This has some similarities to what happens to Solo in his game.