Complex sentence: A second wave of characters was planned for release in 1988 but both the cartoon and the accompanying toy line were cancelled, so these new characters never made it beyond toy industry catalogues and it is not known what role they would have played in the series.
Split into simpler sentences: A second wave of characters was planned for release in 1988. But both the cartoon and the accompanying toy line were cancelled, so these new characters never made it beyond toy industry catalogues and it is not known what role they would have played in the series.