Well... even though I have no key development in this project, I would assume it would be a 3D Platformer, as the original insomniac Spyro series were 3D and it is very possible to make a 3D Platformer in Unity and Unreal engine.
If it were my decision or call to make, (which it isn't) I would prefer to make this with Unity, as it is easier to work with and Yooka-Laylee has proven very successful on it.
On the other Kanieis the Jackalope thread, the OP said her ears were like helicopters, but in my opinion, it would be cute if her ears glided like Spyro's wings. Even when Spyro was idle, his wings would slowly and casually move up and down, if the ears of Kanieis did that, I would squee with joy. I designed Kanieis after Spyro the same way Yooka is designed after Banjo. The Ears look like bunny ears as well as wings, and I didn't include eyelashes the same way Laylee doesn't have eyelashes and is feminine. I hope I styled Kanieies' expression after classic 90's Platformer mascots, while keeping it charming and feminine. It shows she is willing to go on an adventure and kick butt!
Also below is a spyro fangame I've kept my eyes on, proving Unity 3D Platformers can be pulled off.
https://www.youtube.com/watch?v=2DicrivJ2xc
My character Glyde the wasp works as Kanieises companion, helping collect carrots and leaves, and working as a health bar, changing color when you take damage
Trapper the Wolf gives you mission objectives, offering you collectables, granting you progress in the game
And thanks for brohoofing this Tom!