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.
The shipped playable ad: one authored encounter built for a short session — drag the magnet through the loot, grow its pull and breach the vault.
The standalone build plays three levels in sequence, LEVEL 1/3 to 3/3, each asking for a bigger haul past more hazards: the vault target rises from 18 to 24 to 28 pieces, and the hazards from 2 to 3 to 4. Every vault breach advances automatically; the third ends on HEIST COMPLETE.