This page explains how to obtain Ending 1: “The Developers’ Room in Chrono Cross: The Radical Dreamers Edition.
How to Obtain Ending 1
To acquire this quirky ending, you must defeat the Time Devourer with Serge alone, at the very beginning of the game.
We suggest heading to Opassa Beach at the earliest opportunity. Feel free to start a New Game Plus using your newest cleared save file, then speeding through the opening and Lizard’s Rock, while disabling enemy encounters.
For the fight itself, it can be a little rough with Serge alone. If you’re struggling, maybe try this ending last, after you’ve obtained more Growth stars (up to 99) by repeating past boss fights. That said, it’s entirely doable with 48 Growth stars.
It helps if you equip the Green Plate armor stolen from the Green Dragon, since the Time Devourer spams Green Elements for half the fight. After that point, you can cast Diminish to reduce the damage from Elements (also reduces yours) or Negate Magic to nullify all damage.
In the event you missed the Green Plate, stock up on lots of Nostrums for healing, plus Diminish and Negate Magic to reduce/nullify damage.
This ending will send you to another version of Viper Manor, which has two floors of Chrono Cross developers. Feel free to chat to them to listen to their whimsical stories etc. There’s also a sound test on the upper floor, along the east wing. To leave, speak to Solt and Peppor by the entrance.