The Rhombcube is in the Specialty 3x3x3 Cube-like Puzzles section.
Rhombus refers to the shape of each face.
This is a Dodecahedron cube, which means it is a 12-sided puzzle.
This puzzle looks way more complex than a cube, but it is really very similar, its unique shape can confuse when trying to solve it.
Mix up the cube and try to arrange it back to it so each face will have the same color.