Thanks for all the feedback! I'm glad people are finding the game interesting.
Some of you are asking how it was implemented, we bascially had one set of game objects that are the source of truth with physics attached, the other objects are really just the same object but copied to another position with an offset. We do have to limit the amount of objects copied for performance reasons. In the case where the source object is moving too far away from the player, e.g. the player keeps throwing the sphere in one direction, we teleport the object back to the player's room so the source object is never outside the map. We also move the map with the player in case they're moving too far in one direction (for example in the last scene you see).