A continuous-drag collection ad: the magnet follows one finger and the field visibly grows with every stage of the haul.
The magnet tracks a single-finger drag inside the play area. Loot inside the attraction radius is pulled in; at 8 and 16 items the radius and pull strength step up, and at 24 the magnet is vault-ready. Touching a hazard counts a strike, and the second strike fails the run. Dragging the ready magnet into the vault zone plays the vault-opening payoff.
Keep the reward continuous: something is always flying toward the magnet, and each power stage is visible in the size of the field.