RetroGaming

I bought it when it came out and played it a little. My Japanese wasn't great then (it's not all that much better now TBH) but I think I understood enough of it to give it a try.

The game itself is split between a dungeon crawler and a management sim. You go dungeon crawling to capture staff to work on games, and the combat system includes timed multiple-choice options, some of which are related to Sega and Japanese gaming trivia. Then once you leave the dungeon, you create game projects from menus, and assign your captured staff to work on them. Your ultimate goal is to claw back Sega's market share from the Dogma Corporation (standard sentai villains and thinly-veiled Sony stand-ins).

There are tons of Sega and Japanese gaming culture references of course, but a lot of these are either just "Hey, remember this?" (and as a non-Japanese gamer, you might not), or in-jokes that can't really be translated. For example, if you're familiar with the "All your base" meme, imagine trying to translate that into Japanese; it's just not going to work because its enjoyment largely hinges on having "lived through it", and the idea itself resists translation anyway.

I didn't get very far due to a combination of language barrier, lack of trivia knowledge, and the unfortunate fact that after the intro section I just didn't find it all that amusing. I live in Japan now and as far as I can tell, these days people still occasionally talk about it fondly but it's not really considered to be a cult classic here.