It doesn't have to be full time of course, I wouldn't have the time for that either. I don't know the exact details but from my understanding, OpenRCT2 basicall

It doesn't have to be full time of course, I wouldn't have the time for that either. I don't know the exact details but from my understanding, OpenRCT2 basically took a machine-decompiled version of the game and started replacing things with proper code as they went along, fixing bugs, adding things they liked... and just keep the dependency on original game files to avoid copyright issues: if you don't have the original you simply can't play. That might work here as well?