3D Pool

Basically balloons but the helium to envelope ratio would be such that they didn't float to the ceiling, they just stayed at whatever level they were at then the momentum of the hit ran out.

Holes at verious locations around the walls, ceilings and floors would be the targets to knock the floating balls into.

The game would start with a net shaped like a rack in the middle of the room being closed around them to set them up.

Pool cues would include ones with small hammer on one end for hitting balls overhead.