Sonic Mania Launches for PC, is Accidentally Online-Only

Steam users are unable to play the game in offline mode, despite Sega's insistence that the game is intended to be playable offline.
Denuvo's copy-protection system seems to be the problem.

Sonic Mania Launches for PC, is Accidentally Online-Only

Sonic Generations (Video Game) - TV Tropes

New Sonic Mania Patch Accidentally Released Early; Adds Level Transitions, Revamped Boss, & More

Sonic Forces (Video Game) - TV Tropes

Sonic Mania Plus - Official Trailer : r/Games

Sonic Mania Release Date Possibly Revealed by Steam

Sonic Mania Launches for PC, is Accidentally Online-Only

Sonic Mania - The Cutting Room Floor

I dunno if you guys noticed, but Sonic CD's depot was silently updated and now it shows Linux support : r/linux_gaming

Sonic Mania - Xbox One, Xbox One

Sonic Mania

Sonic Mania News - Nintendo Life