when did he appear onscreen?
He had cameo roles in "The Blues Brothers", "Gremlins", "Vanilla Sky", and "Austin Powers in Goldmember"
Steven Spielberg
Spielberg had cameo roles in "The Blues Brothers", "Gremlins", "Vanilla Sky", and "Austin Powers in Goldmember", as well as small uncredited cameos in a handful of other films, such as a life-station worker in "Jaws". 
who shot tom hanks in saving private ryan UNANSWERABLE what is the genre of this film? Epic war film who directed it? Steven Spielberg which actors are there in it? Tom Hanks, Matt Damon, Vin Diesel, among others. has this director's work achieved any academy award? Yes, he has directed fourteen Oscar winning and nominated performances.
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Steven Spielberg [SEP] Onscreen appearances
Spielberg had cameo roles in "The Blues Brothers", "Gremlins", "Vanilla Sky", and "Austin Powers in Goldmember", as well as small uncredited cameos in a handful of other films, such as a life-station worker in "Jaws". He also made numerous cameo roles in the Warner Bros. cartoons he produced, such as Animaniacs, and even made reference to some of his films. Spielberg voiced himself in the film "Paul", and in one episode of "Tiny Toon Adventures" titled "Buster and Babs Go Hawaiian". In 2017, Spielberg, along with fellow directors Francis Ford Coppola, Guillermo del Toro, Paul Greengrass and Lawrence Kasdan were featured in the Netflix documentary series "Five Came Back", which discussed the contributions of film directors Frank Capra, John Ford, John Huston, George Stevens and William Wyler towards recording the events of World War II.