Although Sonic Mania appears to be one of the better entries in the Sonic series, successfully picking up the mantle of classic, 2D action from where Sonic and Knuckles left off, one aspect of the PC port that people aren't too impressed with is the always-online requirement. To play the game, users are finding that it checks their internet connection and sports Denvo anti-tamper DRM too.
However, this is no ordinary tale of a company looking to cash grab of cause problems for players. The way things have been worded, it sounds as if the developer, HeadCannon, may have made a mistake in the Steam implementation of the game.
"Like you, we've noticed an error in the Steam store not mentioning the DRM for Sonic Mania," a post on the game's Steam page reads. "We're fixing that now. Sonic Mania is intended to be played offline and we're investigating reports on that."
Some have suggested that it may be Sega forcing the DRM on to the game, but you would imagine the developers would have been aware of such practices if that was the case.
Whatever the case though, it seems likely that the online requirement of the game will be scrapped in the very near future. The fact that it's impacted the game's reviews on Steam means that that would certainly be a worthwhile move.
In a surprisin turn of events too, the game's support team on Twitter encouraged angered gamers to "make your voices heard" (thanks PCG). That's not the response you'd expect from someone in any official capacity, though it is encouraging.