A heavier R takes more effort to accelerate and turn. The same flick carries less speed when you increase its mass.
Gravity pulls it toward the floor. Air drag slows it in flight; friction takes over on contact. In a vacuum, mass does not change the rate of free fall.
In Spin mode, your grip holds the center while your drag turns the object. Release to let it fall.
Keyboard: ← → turn, ↑ lift, ↓ tip, Space pause, R reset. Hold Shift while dragging to spin.