First of all great game! Second of all, to address how you may want to fix some of the feedback in the comments. If you want the players to have control over their camera zoom you can have two "cameras." One gets all of the relevant camera scripts (in the case where I used it CinenamachieneBrain) The second is a child of the first and only has a script to change its z when scrolling. Then all you have to do is disable the camera component of the first camera and make sure the second camera your main one (leave the other untagged). To fix the mouse evacuating the screen, Cursor.lockState is your best friend.