(Sorry! I am spanish and I will translate poorly)
I liked the game! Your channel got recommended to me in youtube and I came here to see what have you done
You made a platform system that was responsive and cool (tails even could fly!) I would have love you to have taken profit of, like making a mini level for the two characters.
The way you introduced the mechanics in the spin dash zone was pretty amazing! But on first view it was pretty confusing, I couldn't move and I thought the controls were broken, you should add visual response for the player like changing the palette for a moment. The cinematics were cool but very slow. Don't make the player wait more than 60 seconds without nothing moving or changing on screen only to show an end screen. The sprites were cool, and the music was the most polished thing of the game.
Have a beautiful day!