If ever there was a tale of more woe, it's this of Sega and their Sonic Mania. The PC version of the game was delayed by two weeks, making it fall behind its console cousins, which is already enough to make anyone mad. Tack on to that the addition of DRM that wasn't indicated previous to release, and even a meek mouse would cry.
Sonic Mania was doing extremely well for those that started playing the game on PC. Everyone was enjoying it, their nostalgia senses were in full tingle, and things were good. Then some players started noticing a little bit of a “bug," as Sega is calling it. If you weren't connected to the internet or (in other words) trying to run Steam in Offline mode, you couldn't play Sonic Mania. Even the public relations manager working on Sonic, Aaron Webber, took to Twitter to say, “... please do share your feedback on DRM or any issues you're having at the link above. Make your voices heard.”
It's a strange twist of fate that seems to indicate a bit of a storm even behind the scenes. Needless to say fans, certainly did make their voices heard, and Sega actually responded. It wasn't the response anyone was hoping for though, as it would appear Denuvo is definitely still in Sonic Mania. The inability to play offline has been fixed, but you of course have to connect the the internet first to download the patch that fixes the “bug.” Anyone with the inability to connect to the internet at the moment will have to wait to play Sonic Mania.
Sources: IGN, SEGA Europe Twitter