Hades was Supergiant Games first experience with Early Access, which has been a massive success and has helped shape the game for nearly a year.
In an interview with OnlySP, Greg Kasavin, creative director at Supergiant, stated that Hades was designed around the entire concept of an Early Access release so that it could be modularstarting small, and getting bigger over time.
Source: N4G PC Supergiant Creative Director on Hades: Were Treating Early Access Almost Like a Serial TV Series