According to the observations of critics, Oster's aesthetics is distinguished by "stylistic eclecticism, subtext, quotation, play of signers, irony, parody and stylization".
In an anthology of children's literature published in Canada, Gregory Oster with his "Harmful Tips" was the most widely circulated - 12 million copies, while other authors honored a maximum of 300-400 thousand.
In the late 1990s, Mikhail Epshtein and Aleksandr Genis included Gregoriy Oster in the "Who is who in Russian postmodernism" list. In this list, consisting of 170 names, Oster is the only children's writer who "made a contribution to the development of post-totalitarian Russian literature.".