Sonic Mania
The easy praise is "Sonic Mania" being the best 2D Sonic game since at least "Sonic Rush", but I'm struggling to name platformers released within the past decade that challenge "Mania"'s quality (perhaps "Freedom Planet"). "Mania" understands that "Sonic" is about more than speed, utilizing every inch of every frame to communicate in ludic manner when it is wise to slow down. Combine this near-mastery of this style of play with some of the best bosses of the entire series and "Sonic Mania" betters even "Sonic CD", with only a few technical issues and lesser later levels holding it back.
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