Eight of TENTACLE's arms on a head: each with mass, water drag and suckers, all eight in one solve so they press on one another and on the head. Start in 3D, then 4D, where the arms root at a cube's corners. Drag to turn the view. In 4D the pad twists your slice into w (J L, I K), the lever moves it ana and kata (R F), ⊞ or Z squares it up. The readout says what the physics costs your device; on a slow one it drops substeps, then resolution. how it works · TENTACLE · kata