You are using a texture with a size of 512x512 on the widget with size of 712x404 (img - inspector2), so the map loses aspect ratio, and the map looks tilted.
Use the square widget size, to prevent this problem.

It's a very basic 2D scene with the map filling the screen.

Please attach a screenshot of map GameObject.
Most likely you just need to click «Move Camera to Center of Tileset».

I didn't see anything in the Unity Inspector to change the perspective/camera angle of the map--where in the code is this set?