reminded myself of two niche ds/3ds games that i wad obsessed with learning about briefly due to the fact i was researching any and all rpgs on the platform, those two being nanashi no game (nameless game/game with no name) and labyrinth no kanata (beyond the labyrinth).
both of them concern themselves with existing on the ds/3ds as a meta format. nanashi no game initially presents itself as a "you" playing a game that gets ds software downloaded onto your system, and its a game rumored to kill you in 7 days. the story un-metas for a bit as it tells its story but its not immersion breaking. beyond the labyrinth has you playing a simple dungeon crawling rpg multiplayer game on your 3ds with three other pals and things get much more complicated and strange after the first part of the dungeon.
nanashi no game has a sequel too and as far as im aware they both have english translation rom patches. i haven't played the second one but the first one genuinely has some cool survival horror game design while all being relegated to the ds format. there's really nothing else like it. but like all horror games it does have quite a few content warnings in case you want to check it out. this game has its own wikipedia page so its got some amount of recognition. something i completely forgot about before grabbing the trailer is that the cursed game is played with your ds in the normal format and then theres visual novel sections where you turn your device on its side, adding to the weird uncanny way you deal with this game. it's pretty neat!
its been a few years since ive checked in on beyond the labyrinth and after an initial search it seems it's gotten some english patches too within recent years which is great! i was consuming the game mostly through a playlist of someone playing through the game and translating the text as it went. i think it was being done through youtube annotations (especially since some characters dialogue is color coded) so RIP but the gameplay footage is still pretty interesting to look at and i think conveys the conceit of the game pretty well.
i'm eventually gonna hack my 3ds so i plan on playing these on hardware, but if either of these look interesting, please give them a try and tell me what you think!