What: Kingdom Hearts: Chain of Memories is a game in the Kingdom Hearts series released for GameBoy Advanced in 2004, with a remaster made for PS2 in 2008 that would go on to be used for "Final ReMix" ports of the Kingdom Hearts games. It follows off of almost directly after the events of Kingdom Hearts 1 with the main protaganist Sora, along with Donald Duck, Goofy and Jiminy Cricket entering an area known as "Castle Oblivion" after following a man in a black coat (of which there are multiple in this game, a singular (eventually a 2nd in another game) woman included) (spoilers for games in the Kingdom Hearts series from Chain of Memories all the way until 3 hidden). Sora and co. have to go up the castle floors whilst losing their memories (as foretold poetically by a man in a black coat) and revisiting worlds from the 1st Kingdom Hearts game. The game uses a mix of the battle system from the 1st game along with a card system that influences the properties of your attacks, to what enemies you encounter (kind of) and even the order you re-visit the previously mentioned worlds.
How: I'm playing through the VBA emulator, with the game itself having been patched for a Polish translation (thanks to Rykuzushi's efforts).
When: I've started my most recent playthrough about 5 days ago since the making of this Reddit post.
Where: I play at home.
Why: I've already beaten Kingdom Hearts 2 and Birth by Sleep through the 2.5 Final Re:Mix collection (which I played on PS3) and wished to play another game in the series, as watching cutscenes on YouTube with my "get spoiled on the game before getting it" mindset wasn't satisfying me anymore.
My opinion (aka. the part you're most likely to read): I am enjoying my time with COM. The battles are somewhat difficult without being obnoxious despite what the gameplay design choices might entail, the story is intriguing from start to finish and the character interactions are some of the best in the series ironically due to the GBA's limitations. While the pixel art done for the game is absolutely luscious, the same can't be said for the music per the limitations of the handheld, and some rare bosses do fall flat either because of them being on both of the extremes in difficulty. Overall, I'd reccomend the game if you're a fan of the 1st game and you're willing to learn the in's and out's of the card system. Oh, and get ready for tone-shifts galore.