Kill 10 ghosts.

Get a Stamina extension.

Get the Helmet.

Get your first silver key.

Get the Gloves.

Play all of Sergei's routes.

Kidnap the professor and reach Sergei's B ending.

Steal the diamond and reach Sergei's B ending.

Play at least one of Sergei's routes.

Kidnap the professor and reach Hunter's B ending.

Steal the diamond and reach Hunter's B ending.

Play at least one of Hunter's routes.

Get all other trophies