I have seen many people with the same issue as mine. Pretty much everything fits this description:
No fancy settings set, events, and nearest scaling is enabled. Only a sprite or animation loaded. The problem is that the sprite has pixels mishaped all around when the testing starts. Less or none distortion is seen in the editor. Pretty much any resolution results in this situation. Pixels are not displayed in uniform size. No broken numbers for zooms, also. When camera is really (and only really) close to the sprite, the distortion is less, maybe none. No upscalings in the editor either… It seems that most people can’t really reproduce this, but those who go through this issue simply never manage to get over it. That might also turn out to be my case…
For folks to be able to help, you’re going to need to provide some base info:
A screenshot of your project properties, including resolution and scaling settings, along with pixel rounding settings.
A screenshot of all events dealing with zoom.
If you’re forcing fullscreen through events, a screenshot of all events dealing with fullscreen
If you’re not forcing fullscreen through events, details on whether you’re just hitting maximize or not (Maximize will always have distortion if you’re scaling retro art, because the title bar and task bar takes up portions of the available space, making it a non-integer scale)
Details on your display resolution.
More details may be needed after, but that’s the bare minimum before the community can help more.