As the synopsis implies, it is a crossover with Silent Hill. The story is set during Kingdom Hearts II (but contains spoilers for Kingdom Hearts 358 Days Over 2), with Sora, Donald, and Goofy crashing onto a world and finding themselves in Silent Hill without their weapons. The plot has a lot of elements of Silent Hill 2 (including a cameo of James) and contains a lot of speculation of Sora's home life (to be specific, his parents and the sort of people they are). Also, Donald and Goofy are actually featured heavily in the story (compared to what usually happens to them). There are plenty of Silent Hill-esque puzzles along the way, and all in all, worth a read.
FanficRecs Review for The Open Door
As the synopsis implies, it is a crossover with Silent Hill. The story is set during Kingdom Hearts II (but contains spoilers for Kingdom Hearts 358 Days Over 2), with Sora, Donald, and Goofy crashing onto a world and finding themselves in Silent Hill without their weapons. The plot has a lot of elements of Silent Hill 2 (including a cameo of James) and contains a lot of speculation of Sora's home life (to be specific, his parents and the sort of people they are). Also, Donald and Goofy are actually featured heavily in the story (compared to what usually happens to them). There are plenty of Silent Hill-esque puzzles along the way, and all in all, worth a read.