this also caught me by surprise... and, after looking into it, I saw that Nippon Ichi's subscription-based smartphone service Game Variety Unlimited added Jigsaw World and the sequel Jigsaw Island at the end of last month, so I figure Jigsaw Island will probably arrive on Steam in short order, too.
Competitive jigsaw games were one of the pillars of early NIS, believe it or not: their predecessor, Prism Kikaku, developed the SNES/SFC competitive jigsaw game Jigsaw Party/Pieces for the short-lived software division of Hori in 1994, and 1995' Jigsaw World (PS) was their first self-published game as NIS. Aside from World & Island, they did a Rhapsody/Marl Kingdom-themed version for PS2 and a DS version titled Jigsaw World: Daigekitou! Jig-Battle Heroes, and I'm sure I've seen at least one or two adaptations for mobile or browser or whatever as well. Etna's in the DS version, naturally.
This port's completely untranslated, by the way; the sequel did get a super-late intl PS release as "Jigsaw Madness", so there's a chance that port might include English, but I kinda doubt it.
just remembered another version... Jigsaw Party World, one of a few games that were demoed/tested for the PGM2 arcade platform that may or may not have ever made it to market
Jigsaw Island, the aforementioned PS sequel to Jigsaw World
SatelliTV, a simulation game about running a satellite TV station; I've never played this, but I've heard that it's much, much simpler than you might presume a "NIS simulation game" to be
The ONITAIJI: Mezase Nidaime Momotaro, a 4-player boardgame with a Japanese mythology theme, centred on competing to defeat the most demons around Japan in order to become the next Momotaro; I'd never seen this one before now, and my immediate impression is "low-budget Dokapon"
Bishoujo Hanafuda Kikou Michinoku Hitou Koi Monogatari, a PS galge originally developed by NIS and published by FOG, a company whose catalogue was acquired in 2016 after the death of the founder. (NIS' Japanese website hosts an interview with NIS' president on the relationship between the two companies.) This game is very much a precursor to FOG's popular Fuuraiki series: you travel the Tohoku countryside, playing hanafuda against various girls in order to win the right to take their photo, and the mix of drawn/live-action visuals and the tourist-brochure-y info about the setting were expanded upon to great effect in Fuuraiki and beyond.
What in the world.
Maybe I should've seen this coming once NIS started this whole PS1 re-release wave, but "Michinoku Hitou hitting Steam" wasn't on my 2024 release calendar bingo, that's for damn sure.
That said, Michinoku Hitou is a cool little thing. I learned how to play koi koi to beat it! It's still super charming and unlike just about anything else of its vintage until, well, Fuuraiki proper actually came out at the tail end of that generation. Aside from what GSK wrote, I'll also add that it's actually canon to the Fuuraiki series; the secret fourth heroine you can unlock after clearing the other three routes comes directly from this game (different lady than the one in the screenshot). It doesn't have any real bearing on the rest of the series as far as I recall, but it is useful to play this game for background knowledge prior to doing that route if you're intending to see everything there is to see in Fuuraiki.
The fact that NIS is seemingly putting out the original version of this game and not the later Kai redux is something of an eyebrow-raiser, though, assuming they're not just papering over that subtitle for simplicity's sake. The first PS1 release and the subsequent hornier Saturn port are notorious for having brutal hanafuda AI, which Kai softened significantly (as in, to the point that a newcomer like me was able to beat it without too much trouble). You generally don't need to actually win that many matches to progress the story itself, but you do if want to actually photograph the girls in the different environments, which is certainly the main draw. You only receive tokens to take a handful of shots each time you win unless you have a really commanding lead by the end of a match, which means you're in for a shit ton of grinding if you don't resort to cheating.
Anyway, this release kinda fulfills the one fear I've always had about any proper Fuuraiki re-releases in this day and age, which is that the imagery would be handled poorly, given that mix of line art and real world photography. If we assume these are basically just gussied up PS1 emulations, which I think it's safe to say they probably are, then I would never expect them exactly go digging into any FOG vaults to unearth the original photography for this game and run it through a decent upscaling algorithm, but the fact that they seem to have just applied a bilinear filter to everything, including the photography, does this game's aesthetics no favors. Just look at the clouds in the background of that screenshot above; just gross stuff. It's a much more cohesive look at 240p and while that photography would look extra crunchy blown up to HD today, I would hope the option to turn this filtering off at least exists or else otherwise my recommendation would genuinely be to just play Kai on a Vita instead.
I'll still probably buy this thing when it comes out because... it's too left field of a release catering to my tastes not to do so, but what a strange, strange turn of events. I might pick up that jigsaw game they just put out and briefly play it before refunding it just to see all there even is to expect in terms of options for these releases, but yeah.
Found the screenshots I took during my own run of the game a couple years ago stashed on my NAS server. Granted, I played on Vita at an upscaled 640x480 and I believe there's still the slightest filter applied to it because for whatever reason. Vita's screenshotting feature breaks when doing PS1/PSP stuff under any other configuration whatsoever. Either way, hopefully this should give y'all a much better idea of what this game is actually supposed to look like when the game is left untouched at an SD resolution and the photography isn't being completely ravaged. FOG's photoshopping skills markedly improved by the time even the original Fuuraiki rolled around, but on its own, still a look I honestly dig. 
