Game juice
Game juice is the layer of small effects, like flashes, freezes, shakes and layered sounds, that makes an action feel good without changing what it does.
Also called juice, juiciness, game feel effects.
Juice is everything that answers a player's input with extra feedback: a flash on the frame of a hit, a short freeze, a nudge of the camera, a burst of dust, a sound built from several layers. None of it changes the rules. A game with the same rules and no juice plays the same and feels flat.
How much juice is too much?
Effects that pile up hide what's happening. We make every effect smaller than feels natural at first, let only the strongest event of a moment move the camera, and judge the result where players actually fight: at night, in fog and in a crowd, as well as in an empty test room.
Juice in Mytheria
One sword hit has a forward lunge, knockback that takes over the lunge's momentum, a cream flash for 8 frames, 4 frames of hitstop with the screen shake inside them, a lean of about 1.3 degrees for every pixel the target is pushed, a short stroke across the swing and four or five layered sounds. Breaking a rock adds a puff of dust, a shadow that shrinks into the ground and a small pile of rubble.
The full build-up, one effect at a time with real clips, is in our post on combat feel; the rock is in how to make a rock break feel satisfying.
The full post, with clips and demos How to make combat feel good