Hey, I just checked out your game. Supes cutes. I did notice a visual choice which is common among game developers, which I thought you might like to know how to change. You seem to lerp between the camera position and the actual position with a fixed integer position, which causes some visual jitter on the slower movements.
I believe you make games with Game Maker Studio, so this tutorial may not be 1:1, but the principles are pretty easy to follow. The idea comes from a video called "Smooth Pixel Art Camera | Godot 4.4 Tutorial" on YouTube.
Essentially, all you're doing is moving the viewport (scene) around the camera (origin) by offsetting each vertex by the "camera position," which is dictated by your camera movement code. In a sense, your camera doesn't move; the world does.
If you have any interest in implementing this, best of luck!