It has a total of 50 movable pieces to rearrange, compared to the 20 movable pieces of the Rubik’s Cube.
The Megaminx is made in the shape of a dodecahedron, and has 12 faces and center pieces, 20 corner pieces, and 30 edge pieces. The face centers each have a single color, which identifies the color of that face in the solved state. The edge pieces have two colors, and the corner pieces have three. Each face contains a center piece, 5 corner pieces and 5 edge pieces. The corner and edge pieces are shared with adjacent faces. The face centers can only rotate in place, but the other pieces can be permuted by twisting the face layer around the face center.
There are two main versions of the Megaminx: one with 6 colors, with opposite faces having the same color, and one with 12 different colors. The 12-color Megaminx is the only type legal in official WCA competitions, and is therefore much more popular than the 6-color version.
The purpose of the puzzle is to scramble the colors, and then restore it to its original state of having one color per face.