When a capsule lands without eliminating any objects, the flask will fill up. An empty flask requires five capsules to land before it is filled, though some flasks start out partially filled. When a flask is filled, objects will be shot out at random locations. In some stages, the locations in which the objects are shot may be prioritized. The object(s) a flask shoots out differ between stages, and the amount of objects that it shoots out depends on the size. A small-sized flask that occupies one row and one column shoots out either one or two objects, a medium-sized flask that occupies two rows and two columns shoots out either two or three objects, while a large-sized flask that occupies three rows and three columns shoots out either three or four objects. In some stages, the flasks will shoot out objects that are related to the objective(s), such as viruses. If more objects were added from the flask, the amount of objects required to be eliminated will also increase unless the objective is met before more objects are shot out from the flask. With the exception of clouds, if a flask is covered in an object such as ice or barrels, it will not be able to fill until the foreign object is removed. Moreover, when Dr. Rosalina's skill in rearranging capsules is active, landing a capsule won't fill the flask.