OpenKeeper VS Simitone

There's also https://github.com/tonihele/OpenKeeper but it lacks developers.

What you want to do is have the ability for the user to be able to use the assets from an installation they got. You also don't want to use a name which might make it appear like it is affiliated with Firefly or Stronghold. Look at projects like OpenMW, OpenKeeper, or Julius. They all are reimplementation of game engines, none of them were shutdown.

OpenKeeper - Dungeon Keeper 2

For real advice though, check the GBAtemp forums for coding help and the guy that used to be porting Sims 1 to FreeSO's engine (https://github.com/riperiperi/Simitone) might have some insight.

Simitone - Re-implementation of The Sims 1, based off of FreeSO.

That's not just UI. That's an entire reimplementation of the game. https://github.com/riperiperi/Simitone

Or you can just play Simitone? https://github.com/riperiperi/Simitone Works great

According to [1] "EA only demanded us not to port the game on mobile devices"; that's the only thing I could find.

It's still on GitHub anyway: https://github.com/riperiperi/Simitone

Looks like the main dev mostly moved on to https://github.com/riperiperi/FreeSO

[1]: https://mobile.twitter.com/Simitone/status/12027483512272691...

Hell, it's already happening for Sims 1 and Sims Online.

It's at the point where some very popular older games (eg. Rollercoaster Tycoon, Sims 1/Sims Online, Elder Scrolls II: Daggerfall and Elder Scrolls III: Morrowind) are all getting re-implemented with custom-built open source engines or re-implemented into new engines by the community still playing those games which essentially means they'll likely be playable and getting new content for a very long time into the future. There's also modpacks aimed at being an easy way to have a "remastered" version of the game, for example there's one for 2005's Star Wars Battlefront II, a project aimed at remastering all of Rockstar's PS2-era titles/including a fixpack for the official GTA remasters and two projects aimed at remastering hit n run, one by modding the original game and the other by importing it into UE5. (There's also another person making their own Futurama game by modding Hit n Run)

Speaking as someone who plays a lot of retro games, you're almost always better off running one of the already existing software API converters even on AMD or nVidia hardware these days if there's no open-source engine reimplementation that allows you to just run the game with modern code and other tweaks to help modern systems along. (eg. OpenRCT2, Simitone, OpenMW, etc) There's a lot of reasons as to why but essentially it all boils down to the simple fact that the older versions of DX and OpenGL aren't fully supported on modern GPUs, they're supported and probably tested to a certain degree but they're also a much lower priority than say, making sure the hot new FPS launching next month has a driver update that ensures it'll work well.