Lego has confirmed further details of its new Donkey Kong arcade machine set, revealing exactly how its endless-barrel mechanism works and that Nintendo requested one specific design change during development. Designer Carl Merriam, whose past credits include the Lego Game Boy and Piranha Plant, told The Verge that Mario creator Shigeru Miyamoto is reportedly "very happy" with the finished set, even though he has not met the designer directly.

The set includes a working joystick and jump button for Jumpman (later renamed Mario), plus a lever that releases a continuous stream of barrels using the same barrel piece Lego first produced in 1989. Merriam revealed the barrels are propelled by a pump-like mechanism using a 14-barrel internal stack that can hold up to 20 barrels at once, allowing six to roll down simultaneously before collecting in a hopper. He also disclosed that Nintendo's sole feedback was a request to make the "poison" barrels heavier by adding minifigure heads inside them, and confirmed the new Jumpman minifigure element is detachable.