Kotoro By: Semidome Inc. Kotoro is a color-mixing puzzle game by Semidome. You have to combine colored bubbles to create the goal color, with it left as the only bubble. It can be tricky, so this walkthrough guide should help you if you get stuck. Feel free to ask for extra help in the comments section. Walkthrough: Chapters 1 Collision & 2 Swap: Chapter 3 Replicate: Coming soon!