Hmm... In Outer Wilds your ship is moving in 3D space, close to objects with gravity (some of them moving) and you control thrust and rotation on multiple axes

Hmm... In Outer Wilds your ship is moving in 3D space, close to objects with gravity (some of them moving) and you control thrust and rotation on multiple axes while looking through a small porthole. In Flappy Bird you repeatedly press a single button to flap. I don't think they're remotely comparable, but YMMV!