If you're playing in English, you can try these codes (you don't need to type ""):
"think about gramps" - Unlocks Access to Gramps' Dojo from the Nexus along with access to the Nexus from there.
"think about arc" (Variants "think about arcgames", "think about arc games", "think about thearcadean", or "think about the arcadean") - A funny skit with maybe a picture of Arc doing coding?
"whistle" - Unlocks Power Endless Air and Access to Water World
"think backwards" - Empty void... A good place to take a nap.
"key" - A special message for those that took enter key literally.
"help" - Pixie somehow explains how this mysterious place functions.
"clap" wasteland
如果是玩中文版，英文沒反應的話，可以試試翻譯後的詞組，例如想想爺爺、鑰匙、拍手等等，但不同翻譯版本的詞可能會不一樣