PentaBlox is a single player, shareware implementation of the traditional puzzle Pentominoes. Pentas are shapes made from five connected squares, this means that they all have the same area but a different shape. The player’s task is to fit the shapes into a box. There are twelve shapes in total which must be fitted into a box. The shareware game has just a 6x10 box but the registered game has three other box sizes 5 x 12, 4 x 15, and 3 x 20.

Pieces may be rotated and/or flipped in order to position them in the box and there’s an optional grid setting to help with the planning.