A blade sweeps back and forth over a cake, log, cheese or chocolate bar, and you tap SLICE when it hits the dashed line. Early cuts are simple halves; later ones ask for 1:2 or 1:3 ratios while the blade accelerates, pauses and speeds up in zones. See both halves with their percentages, and chain perfect cuts under 2% error for streak bonuses.
By how far off the target it is, as a percentage of the item's width; under 2% is Perfect.
Yes, the same seed gives the same items, ratios and blade patterns.
After a few seconds the item is a Too slow 0.