Remastered collectathon for Windows, originally from the Sega Saturn. Free on Steam when you link your account to Sega (though I don't think you need to sign up for anything else and you can probably unlink as soon as the game is added).

As part of linking/claiming you'll be sent to a long URL which starts with localhost:3000 and won't load, just change that bit to sega60th.com and it'll work fine (more details in this post).

I'm posting this on a Friday as it might end up being free forever, but equally the offer might stop at any point!