2D Geometry dash-like ship physics

What I need to do is have my player rotate on it's Z axis according to it's velocity, like this. Unlike the video, my player's X position never changes. Here is my code (JS):

 function LateUpdate (){
 
 player.transform.rotation.z = player.rigidbody2D.velocity.y;
 
 }

When I touch the ground, my player twitches uncontrollably, and when I am off the ground (at any point) my player is flipped upside down.