Complex sentence: This game also marks the introduction of rainbow bubbles into the series-bubbles that are initially transparent and filled with a rainbow but the first time any adjoining bubble is burst switch to that colour, allowing the player to build up chain reactions.
Split into simpler sentences: This game also marks the introduction of rainbow bubbles into the series-bubbles that are initially transparent and filled with a rainbow. Any adjoining bubble that is burst, the rainbow bubbles next to them switch to the colour of the burst bubble, allowing the player to build up chain reactions.