Time Hollow is an adventure game for the DS released by Konami in 2008. The game's story follows Ethan Kairos, a teenager that wakes up on his seventeenth birthday and discovers that his entire world has changed. His parents have disappeared, he lives with his hotheaded uncle, and a mysterious girl named Kori has joined his class at school. Early on, Ethan discovers a device called a Hollow Pen that allows its user to stop time and open a portal to the same location at a different moment in the past. He uses the Hollow Pen with the intent to return the timeline to its original state, but soon finds that someone or something is sabotaging his efforts, hurting his friends and family in the process.
Players can create a portal to a different time in the current location. Whilst the portal is open, everything and everybody stop moving except for those who posses a Hollow Pen.
In the game, flashbacks appear whenever the past is altered. Ethan can use the Hollow Pen in the location of the flashback once the description, location and time of the place of the event is known.
Once the portal is open, players can interact with the past. For example, players can take a letter from the future, and put it in the past where someone important will stumble across it. Closing the portal consolidates the changes that have been made, which will in turn change the present.
However, players can only use the hollow pen a certain number of times a day. When its charges (described in the game as the user's 'Time') run out, Ethan collapses and the game is essentially over. Time can be regained by finding Ethan's pet cat, Sox.
Every time players have a flashback, necessary information can be found by talking to characters, going to the library, or visiting locations. Once enough information has been obtained, Ethan can then use the hollow pen on the location, then modify the past. If the change is incorrect, the same flashbacks will appear, and the portal will have to be opened again. Once the correct changes have been made, the story will move forward with reality reflecting the changes that have been made.
- Ethan Kairos: The protagonist and holder of the Hollow Pen.
- Sox: Ethan's pet cat.
- Timothy Kairos: Ethan's father and previous holder of the Hollow Pen.
- Pamela Kairos: Ethan's mother.
- Derek Karios: Ethan's uncle and Timothy's brother. Takes care of Ethan in the alternate reality where his parents are missing.
- Irving Onegin: The mysterious owner of a local antiques store.
- Kori Twelves: A girl who appears in Ethan's class in the alternate reality where his parents are missing.
Time Hollow is divided in chapters that basically take up one in-game day, with the exception of the epilogue that spans over a longer time period. The different chapters are:
- Prologue: A new day
- Chapter 1: The day that vanished
- Chapter 2: The day that changed
- Chapter 3: The day of memories
- Chapter 4: The day far away
- Chapter 5: The day of resolutions
- Chapter 6: The final day
- Epilogue: A new day dawns
Time Hollow's story is structured in such a way that allows for the story to continue, after a fashion, in a second playthrough. In repeat playthroughs, new story paths are opened leading to alternate endings, including a conclusive ending in which time is not allowed to repeat itself.
- All the main characters names bear one of the twelve numbers of a clock in their family names.
- Both the café "chronos" and the second hand store "aeon" are references to Time.
- The main protagonist family name "Kairos" is an ancient greek concept of being able to define time.
- The restaurant referred to as Eterna is likely a reference to the Switzerland-based company of the same name, famous for their many watch oriented innovations.