Hi, thank you. I actually planned this in version 2.0, where players would be free to use three options: 1. Full screen (forces the character to fill the entire screen, making it appear flat depending on the resolution).
2. Fit center (where the player will see a black area like the current one).
3. Crop center (where the engine will crop the necessary parts so the screen is completely full and centered, but the downside is that some content will be cut off).
For the time being, while waiting for the version 2.0 update for full screen, I recommend using the Visustella plugin and changing the screen resolution to 1280x720.
I hope this helps, and thank you for supporting the purchase of the joystick plugin. Good luck with your game.