Question: Terry Pratchett's The Colour of Magic two-part television adaptation starred an American actor best known for playing Mikey Walsh in what 1985 film?

Context paragraphs:
Colin Smythe: Colin Smythe is a publisher based in Buckinghamshire, UK.  He is arguably best known for publishing the first five Terry Pratchett novels and later acting as Pratchett's agent.  In 1971, Smythe published Konstantin Raudive's "Breakthrough", the first book in the English language on the Electronic Voice Phenomenon (EVP) and the inspiration for the film White Noise.  Other clients include George Moore, Lady Gregory, and Oliver St John Gogarty.

Windmills of the Gods (miniseries): Windmills of the Gods is a 1988 American two-part television miniseries directed by Lee Philips and starring Jaclyn Smith and Robert Wagner.  It is based on the novel of the same name written by Sidney Sheldon, who also served as executive producer.  It was broadcast in two parts by CBS on February 7, 1988 and February 9, 1988.  It was the fifth miniseries based on a Sheldon's book, and the third adaptation starred by Jaclyn Smith.

Wyrd Sisters (TV series): Wyrd Sisters is a six-part animated television adaptation of the book of the same name by Terry Pratchett, produced by Cosgrove Hall Films, and first broadcast on 18 May 1997.  It was the second film adaptation of an entire "Discworld" novel (following the "Welcome to the Discworld" short, which was based on a fragment of the novel "Reaper Man", and the "Soul Music" series).

Soul Music (TV series): Soul Music is a seven-part animated television adaptation of the 1994 book of the same name by Terry Pratchett, produced by Channel 4 Television Corporation/Cosgrove Hall Films/ITEL/Ventureworld Films and distributed by Channel 4 Television Corporation (1996) (UK) (TV) & Vision Video (2001) (UK) (DVD).  It was first broadcast on 12 May 1997 and released on DVD in 2001 alongside Wyrd Sisters in a box set entitled "Soul Music".  The feature-length miniseries was developed by Acorn Media, and directed by Jean Flynn.  It was the first film adaptation of an entire "Discworld" novel (following the "Welcome to the Discworld" short, which was based on a fragment of the novel "Reaper Man").  The series soundtrack was also released on CD, but the disc is now out of production.  The soundtrack is, however, now available through iTunes.  Editz did the title sequences, Flix Facilities did the digital picture editing, and Hullabaloo Studios did the audio post-production.

Terry Pratchett: Sir Terence David John Pratchett, OBE (28 April 1948 – 12 March 2015), better known as Terry Pratchett, was an English author of fantasy novels, especially comical works.  He is best known for his Discworld series of 41 novels.  Pratchett's first novel, "The Carpet People", was published in 1971.  The first Discworld novel, "The Colour of Magic", was published in 1983, after which he wrote two books a year on average.  His 2011 Discworld novel "Snuff" was at the time of its release the third-fastest-selling hardback adult-readership novel since records began in the UK, selling 55,000 copies in the first three days.  His final Discworld novel, "The Shepherd's Crown", was published in August 2015, five months after his death.

Terry Pratchett's The Colour of Magic: Terry Pratchett's The Colour of Magic is a two-part television adaptation of the bestselling novels "The Colour of Magic" and "The Light Fantastic" by Terry Pratchett.  The fantasy film was produced for Sky1 by The Mob, a small British studio, starring David Jason, Sean Astin, Tim Curry and Christopher Lee as the voice of Death.  Vadim Jean both adapted the screenplay from Pratchett's original novels, and served as director.

Welcome to the Discworld: Welcome to the Discworld is a short (8-minute) animated television adaptation of a fragment of the "Reaper Man" novel by Terry Pratchett, produced by Cosgrove Hall in 1996.  It was the first film adaptation of a "Discworld" novel and was followed by the TV series "Soul Music" and "Wyrd Sisters".  The rest of "Reaper Man" was not filmed.

Sean Astin: Sean Patrick Astin (born Sean Patrick Duke; February 25, 1971) is an American actor.  He is known for his film roles as Samwise Gamgee in "The Lord of the Rings" trilogy (2001–2003), Mikey Walsh in "The Goonies" (1985), and the title character of "Rudy" (1993).  In television, he appeared as Lynn McGill in season five of "24" and voices Raphael in the 2012 Nickelodeon "Teenage Mutant Ninja Turtles" TV series, Oso in the Disney Junior show "Special Agent Oso", and Chester The Cat in "Bunnicula".

Terry Pratchett's Hogfather: Terry Pratchett's Hogfather is a two-part television film adaptation of "Hogfather" by Terry Pratchett, produced by The Mob, and first broadcast on Sky One, and in High Definition on Sky1 HD, over Christmas 2006.  First aired in two 1.5-hour episodes on 17 and 18 December 2006 at 20:00 UTC, it was the first live-action film adaptation of a "Discworld" novel.  In 2007, the two episodes were rerun on Christmas Eve and Christmas Day respectively on Sky One and Sky1 HD.

Terry Pratchett's Going Postal: Terry Pratchett's Going Postal is a two-part television film adaptation of "Going Postal" by Terry Pratchett, adapted by Richard Kurti and Bev Doyle and produced by The Mob, which was first broadcast on Sky1, and in high definition on Sky1 HD, at the end of May 2010.

Supporting paragraphs: Terry Pratchett's The Colour of Magic Sean Astin
Answer: The Goonies