Building blocks are popular children's toys, and Yavsoft have taken the concept onto the computer with a range of 3D puzzles for adults to solve.

Launch the game and you are presented with a playing field containing a 3D wire-frame model, surrounded by a bunch of 3D shapes. Your task is to place the 3D shapes in the correct position to create the solid version of the wire-frame model.

Shapes can be rotated, raised or lowered and, of course, moved across the playing field. Control is via mouse or keyboard, whichever you prefer.

It may sound easy but, unless you have a firm grasp of spatial relationships, it could be bit of a challenge. The task is made more difficult by the fact that each puzzle has a huge number of possible solutions, the smallest being solvable in 240 separate ways.