Managa and anime series Fate/kaleid liner Prisma☆Illya has previously announced an animated movie adaption with no release date revealed. The movie, Fate/kaleid liner Prisma Illya Yukishita no Chikai（劇場版プリズマ☆イリヤ 雪下の誓い）, eventually confirmed on Twitter today (24th February) that it will premiere in this year. A key visual is also attached in the said tweet.
Fate/kaleid liner Prisma Illya is originally an alternative universe spin-off of visual novel game Fate/stay night. It started out as a manga illustrated by Hiroshi Hiroyama, and has been made into four seasons of TV anime series.