I'm making a 2D game (since I'm not able to create 3d models and textures on my own), but I want objects' colliders to consider depth. So I have my 2D sprites. I tried to add a RigidBody (3D one) and a 3D collider, but it doesn't have same shape as my sprite. How can I adjust it or change my sprite to flat 3D object? EDIT: I probably should have been described my game better. Player moves a spaceship with accelerometer and have to avoid different obstacles (for now only asteroids). They should appear behind the spaceship and then approach to it (so I've set their Z position correctly, but I haven't realised that 2D physics doesn't consider depth). When they have same Z position as player, spaceship should be destroyed and the game is over.