The Meilong Mirror Cube is the best introduction to shape modifications, because it is mechanically identical to a 3×3. Everything you already know applies. What changes is that the pieces are different heights, so a scrambled cube is a jagged lump and you solve by shape.
That is a bigger change than it sounds. On a normal cube your eyes do most of the work. Here they cannot, so you track pieces by size and position instead, which is why a solver who averages twenty seconds on a 3×3 will take minutes over their first mirror cube.
The Meilong Mirror Cube turns properly instead of seizing up after a week. It is the cheapest genuine puzzle in the range. It makes a good present for someone who solves a 3×3 and thinks they have run out of challenges.

