What did you like best about Sonic 2? Was it the original, varied and yet level design? The clever bosses that never repeated an idea? The game design which is involved and challenging, but still only uses one button? Well, you better go play Sonic 2 and 3 then, because this steaming pile of refuse does the exact opposite of everything I mentioned.
The Sonic sprite is rendered with a shader to have only the three tones of blue in his Sonic 3 sprites that clashes with everything else in the game including other images of Sonic which are shown with normal shaders.
The art design is recycled from previous games wholesale with tweaks to upscale it believably to modern resolutions. And I don't mean like Sonic 2's Emerald Hill Zone compared to Green Hill Zone, Splash Hill Zone straight up lifted the tileset from Emerald Hill and there isn't a single new enemy desgin until you get to the third zone.
The boss designs are also copied shamelessly from the Megadrive games. I will grant Sega that there is purpose in revisiting the classic Ball and Chain Robotnik from Green Hill Zone Act 3 as it is one of the most iconic bosses from that era of gaming. I vocally sighed when I saw the boss of Casino Street Zone (just what you think it is, with a twinge of Carnival Night) was the Neon Claw Robotnik from Casino Night Act 2.
If that's not bad enough, they completely missed the point of the bosses as well. Oldschool Sonic bosses were great in how they were a quiz of the mechanics taught in the zone. With Ball and Chain, you had to have paitence and basic use of the platform to reach Robotnik and avoid damage. Claw forced you to use the spin dash to go up the walls to avoid him grabbing you and sucking out your rings. Both of the aforementioned things can be completely ignored with the basic application of the homing attack, begging their inclusion at all. They do go into a different and new attack pattern after 5 hits, but why not do something FULLY original if that's your goal?
The addition of the homing attack adds nothing to the game other than removing any semblance of game design based challenge based upon platforming. There is still plenty of hard work to do though; fighting the incredibly buggy, awful physics (it is possible to *walk* around a loop with no momentum) and puzzles.
Yes, I said puzzles. Someone that developed this idea thought that placing a puzzle that completely forced you to a stop until you light up a specific set of torches that lowers a wall to allow you to continue in a franchise where speed and flow are *paramount* was a good idea.
DO NOT BUY THIS GAME FOR ANY REASON. The fact that it was ever considered shippable is insulting. If you want a good modern Sonic game, vote with your wallet for Generations.