DIRECT ANSWER
How Do You Attach to a Wall in Meccha Chameleon?
Move close to a wall, object, or other suitable surface, then press Space to attach the Hider.
Once attached, press Space to move upward, press Ctrl to move downward, use A and D to rotate left or right, and press Shift to detach.
After choosing an angle, hold the right mouse button and use WASD to move or pan the Hider along the surface.
Near a surface, Space attaches the Hider. While already attached, Space moves upward. In painting mode, pressing Space once switches to the 3D eyedropper.