Is it obligatory to return the price of stolen PlayStation games to their owners, knowing that these games contain forbidden elements? And is returning the price considered aiding in sin?

It is not permissible to play electronic games that include music, forbidden images, or other forbidden elements. Selling them is also forbidden. If CD-ROMs containing these games are stolen, their value is guaranteed based on the value of the bare CD-ROMs, not the value of the forbidden games. The value of the CD-ROMs must be returned to their owners, or given as charity on their behalf if they cannot be reached.