are there any child actors in the movie?
Yes, Henry Thomas,  Drew Barrymore
E.T. the Extra-Terrestrial
Having worked with Cary Guffey on "Close Encounters of the Third Kind", Spielberg felt confident in working with a cast composed mostly of child actors. For the role of Elliott, he auditioned hundreds of boys before Jack Fisk suggested Henry Thomas for the role because Henry had played the part of Harry in the film "Raggedy Man" which Jack Fisk had directed. Thomas, who auditioned in an Indiana Jones costume, did not perform well in the formal testing, but got the filmmakers' attention in an improvised scene. Thoughts of his dead dog inspired his convincing tears. Robert MacNaughton auditioned eight times to play Michael, sometimes with boys auditioning for Elliott. Spielberg felt Drew Barrymore had the right imagination for mischievous Gertie 
which actress contributed to developing the voice of e.t. the extra-terrestria Pat Welsh are there any sequels of it in the short film genre? Yes, "A Holiday Reunion" was there any sequel that got canceled? Yes, "E.T. II: Nocturnal Fears" what was the reason for that? Spielberg  felt it would do nothing but rob the original of its virginity. did spielberg direct it? Steven Spielberg
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E.T. the Extra-Terrestrial [SEP] Casting
Having worked with Cary Guffey on "Close Encounters of the Third Kind", Spielberg felt confident in working with a cast composed mostly of child actors. For the role of Elliott, he auditioned hundreds of boys before Jack Fisk suggested Henry Thomas for the role because Henry had played the part of Harry in the film "Raggedy Man" which Jack Fisk had directed. Thomas, who auditioned in an Indiana Jones costume, did not perform well in the formal testing, but got the filmmakers' attention in an improvised scene. Thoughts of his dead dog inspired his convincing tears. Robert MacNaughton auditioned eight times to play Michael, sometimes with boys auditioning for Elliott.