Expanding on your idea, I thought it would be interesting to have an MMORPG with multiple completely different clients. The easiest example might be in a future/sci-fi game, you have a normal game client for people moving around the game, and a Stock market client for people who want to play the stock market in the game. You could have a business simulation client as well maybe for shop keepers. Maybe a news website to try and bridge the gap between them all, but you could play one game (the stock market game) while never logging into the First Person "MMO" client but you're completely integrated. If you could think of a number of these different clients, I think it would be interesting.
I love this idea for so many games, but I'll try to stay on topic.
From elsewhere in thread, heavily snipped:
games like that aren’t fun. It’s been tried. [...] hopping online to go do your second job [...] implies work [...] no one wants to do that work
I wouldn't want to do data entry in an FPS game, no, but people love "bakery simulator" type resource management games. It would be cool to link my grocery-line-time-waster score into my overworld bank account, enabling me to shop around for gear in stores set up (but not manually run) by other players, to use in the FPS portion of the game where I steal morsels from the full-sized humans (or am I getting my threads confused?).
EVE tried this with Eve Online + Dust 514 which was a PS3 exclusive. There were cool concepts like having your space ships show up to air strike the planet as they were fighting on the surface. It was interesting but ultimately Dust felt extremely low stakes in the world of EVE. I can’t really speak to its other problems I only tried it once or twice.
Dust 514 was a really, really cool idea that was dead on arrival because CCP (the company behind Eve) released it on a platform that was nearing the end of its lifecycle, and refused to release it on any other platform. It also had to introduce the Dust players to a fair number of the Eve mechanics, particularly around loadouts (fittings) and the economy.
The fact that the spaceship game was intertwined with the team-based FPS was really cool. FPS players (on planets) could be in the same clan/guild/corp as the spaceship pilots, and could call in airstrikes. In the spaceship game, your corpmates could maneuver into position and rain down lasers. This interaction had an effect on the local economy, which was an incentive for the spaceships to show up for airstrikes.
Yeah, I imagine a challenge would be making a second really fun game in a different genre from the first. The different 'games' would probably have to be relatively lightweight and lean into the fact that it's the interaction that is the fun part. Having a space MMO developer somehow land a super popular AAA FPS would be near impossible. I like how the battlefield games let you fly airplanes, but then it's not really a full blow flight simulator.
I'm a huge fan of API-first design and would love to see MMOs embrace this. Anything you do in game could be doable via APIs and those could be open to 3rd-party clients. That would allow people to develop those kinds of specialized clients.
I agree, I've always thought it'd be cool to develop a game that, for instance, you could meaningfully play from a full fledged console or a mobile phone. They might be different components or aspects of the game, but both would contribute to your world/quest/whatever. And just like real life, some people might specialize, and only ever play one aspect of the game, while others focus on other parts.
