Hey, It looks beautiful, the art assets, and the way everything is animated looks like it has a lot of care. I know it’s a WIP, but there are some core game design things that seem not be in the trailer at least.
I want to fly, I want speed. The feather (coin) mechanic is boring and old. Only have it in there if it adds to the experience. And that is what I think this is missing. A unified ‘aesthetic’ in game play mechanics. Having the vertical zig-zag, breaks my momentum, and I want to feel like i’m soaring through a world. I recommend the flying mechanic for super Mario World for SNES as a reference. I find it very rewarding. I like your speed boost tunnels, I think having some enemies that you would have to bounce off of to extend your flight time would be fun too, and it ramps up in difficulty, in a satisfying way.
I think there could be some amazing game play directions to take this game in. I think a mix of a Cannabalt runner, with a plat-former, topped with some exploring-multiple-path-story-elements, could be fun.
But anyway, just some from friendly suggestions-- the art looks amazing. I want to see the game play fly that high as well!
Looks like a solid project!