In this stand-alone add-on to Collapse, the events start out directly after the end of the original game. These additional four chapters describe the return of Rodan to "The Hole".
The anomaly is not gone with its destruction, but is splitted in multiple pieces. Each of them is used by alien creatures to teleport. Military forces secure the perimeter, while new formed bandit groups try to survive in this hostile place. Rodan calls Professor Gorin on his arrival and his only goal is to reach him.
As Rodan breaks his way through all the enemies to the faithful Professor, he will encounter both familiar monster creatures and new ones. The place where Rodan was kept he can't remember, but his abilities were raised an a new trait has evolved - The Rage. Rodan is not such a cold-blooded person, but the rage make him so angry that he may slash his victims with a single touch.
The add-on comes with many features that improves the replayability of the story mode such as achievements (50 items), arena (4 maps), trials (certain goals to reach uncovered with the story progress) and ab experience/rank/upgrades system. The latter means that by using certain weapons (sword, in particular) will give experience to the protagonist. Each level of experience gives additional points which the player may assign to his sword fighting styles to upgrade them.