Biliūnas is considered to have two distinct periods in his literary career. The first spans the years 1900-1903, and the second, 1904-1907. Most of his works are short stories, and often have autobiographical inclusions dealing with his own personal life's experiences. In the first period, a realistic style imbued with a strong social consciousness is prevalent in his writings. Two of his works from this period include "Be darbo" (Unemployed), and "Pirmutinis streikas" (First Strike). The political ideology of a socialist nature permeate this period and are reminiscent of the early writings of Jack London and Theodore Dreiser. Possibly as a result of his debilitating illness, which in that time period was inevitably fatal, Biliūnas underwent a spiritual metamorphosis. His political activities and interests were supplanted by a melancholy, and a departure from realism, which were now manifested in his writings of the second period. "Brisiaus galas" (The End of Brisius), is a tear-jerking recounting of the demise of a family dog with the thoughts of the dog interspersed with the thoughts of his owner. "Ant Uetlibergo giedra" (Fine Weather on the Uetliberg) is almost a travelog of his perspective of the Swiss Alps near Zürich. "Liūdna pasaka" (A Sad Tale) is his longest work and is a psychological drama dealing with the Uprising of 1863. In this work the main character, a woman, is driven to ruin as a consequence of the uprising, and her story is told from a psychological vantage point. During the period between 1900 and 1905, Biliūnas wrote approximately fifteen poems, including several sonnets. These sonnets were influenced by his studies of Petrarch. Most critical reviews of his poems are of the opinion that they fall short of his other writings. Biliūnas wrote several articles concerning literary criticism, which are highly regarded and considered to show his depth of perception concerning the subjects he dealt with.