Sigma is a free, first-person mini-adventure game for Windows PC. Put yourself in the role of a traveller who awakens with an amensia to find themselves lost in a strange compound. You have no recollection of your past, your whereabouts or your direction. You have nothing to guide you except for a strange hand-written letter. You must explore the surrounding environment with a hope to discover both your identity and that of a enigmatic creature or organisation known only as ‘Sigma’. The download size of Sigma is 18MB.