Juicee is a game-feel toolkit for Godot 4: screen shake, hit-stop, squash and stretch, particle bursts, damage numbers, 117 effects in all. It's free and MIT.

The quickest way in is one line from any script:

Juicee.shake_camera(self)
Juicee.hit_stop(self)
Juicee.hit_spark(enemy, Vector2.LEFT)
Juicee.damage_number(enemy, 42)

If you'd rather tune things by eye, add a JuiceePlayer node and build a sequence in the Inspector. Every row has its own play button, and hovering a row plays that effect on a copy of your own sprite, so you see it before you run the game. One player can hold several sequences and play them by name, like an AnimationPlayer. For anything with branches or loops there's a graph editor in the bottom panel.

A lot of the work went into what happens when effects pile up, because that's where hand-made tweens fall apart. Two shakes on one camera both show, and the camera still ends up where it started. Two hit-stops in a row don't leave the game frozen. Calling stop() halfway puts the music, the overlay and the sprite back the way they were. And if two effects fight over one property so that one of them can't be seen, Juicee says so in the Output.

A few more things:

• You can change values while the game is running and feel the difference straight away.
• Accessibility switches for reduced motion, flashing, screen shake, chromatic effects and vibration are respected by every effect, and there's a ready-made options panel for them.
• A switch in Project Settings shows 289 extra parameters when you want finer control.
• Your own effects go in a folder you list in Project Settings, and they show up next to the built-in ones.
• The whole API works from C# as well, with the .NET build.

Needs Godot 4.3 or newer and works in all three renderers. Docs, examples and the changelog are on GitHub: https://github.com/Kelpekk/Juicee