After so long as a Sonic fan myself and people talking so badly about this game, I finally gave it a try, and I wish I never did xd
I can AT LEAST see what they were trying to conceive with this game, it hurts my whole being to see such a huge potential go to waste...

The game itself is beyond rushed in so many aspects: Absolutely terrible loading times, barebones controls and full to the brim with bugs and glitches, not to mention the game's performance is atrocious at best. Everything that could've gone wrong here REALLY did.
In terms of level design, it's a 50/50 to me: Some levels are fair towards the player with their structure, while others are a total mess, especially in the sense of objects and enemy placings.
The story of the game is not exactly a good one, either. The dialogues between some characters feel lazily written and kinda forced, and a few of them (i.e Elise) were pretty much only present for the sake of the story and I didn't feel like they had a real motive to do what they do, honestly. Although, I appreciate the majority of the main cast being in character, that was really nice to see.

I guess it does have some redeemable factors, like the decent graphics and, of course, the awesome OST that distinguishes the Sonic series so much, but it quickly gets overshadowed by how messy and unpolished every single other aspect of the game is. It's infuriating, pathetic and most importantly, NOT FUN.