No cheat codes exist for B-Cubed. It's a browser-based puzzle game (Coolmath Games) where all progress is skill-based. The game runs in Flash/HTML5—no external cheat engine interacts with it reliably.
Level 15 requires navigating a narrow spiral with 1-tile bridges. Key insight: use the vertical walls to reorient by rolling against them. The block's "thin" state is your bridge-crossing tool. Enter the spiral from the correct angle (usually bottom-left approach).
Persist. The solution clicks suddenly.