The objective in the game is to combine atoms into molecules in such a way as to leave no "orphan" atoms. Anyone who's taken chemistry will perhaps remember (not me) that each atom has a valance (look it up ;) ) of one to four, i.e. they can combine with one, two, three, or four other atoms. A complete molecule is defined simply as a structure of atoms in which there are no more free combinations. In each level, you must create a specified number of molecules from (randomly generated) atoms to move on to the next level. A very interesting game that is more original than you think. Also gets incredibly addictive in later levels when your screen quickly fills up with atoms. Highly recommended for all puzzle lovers.

Note: The crack for this game doesn't seem to have removed the copy protection for "game mode B", while "mode A" works fine. This is the long-lost English version, thanks to Richard :)