Flappy bird is not a platformer, but it's side scroller.
Essentially you have only collision handling and the little physics that goes in the bird is isolated from other elements so it's really simple to implement.
The level, you should think about it in small pieces, like say each up and down pipe plus any elements in between, and then you can either use functions to instantiate this sequence of pieces from a description as they pass or use some variation of it for random generation as they pass.
I think for it you could use a screensize room and use room overlays for the game pieces, and then handle the collisions yourself in script - simple AABB collision would probably work fine.
Essentially you have only collision handling and the little physics that goes in the bird is isolated from other elements so it's really simple to implement.
The level, you should think about it in small pieces, like say each up and down pipe plus any elements in between, and then you can either use functions to instantiate this sequence of pieces from a description as they pass or use some variation of it for random generation as they pass.
I think for it you could use a screensize room and use room overlays for the game pieces, and then handle the collisions yourself in script - simple AABB collision would probably work fine.