Description taken from Arcade version of this game

Arkanoid is an updated take of the Atari classic Breakout, which was a hit in the Arcade as well as in the home on the 2600. Arkanoid has updated the brick-busting genre by adding several new elements to the play. Whereas Breakout only offered one wall to break, Arkanoid has many levels, each with different arrangements of bricks. There are also different kinds of bricks that react differently when hit. The multi-colored bricks disappear normally, but silver bricks take multiple hits to destroy, and gold bricks cannot be destroyed at all. Also, some of the multi-colored bricks contain "power pills" which roll down the screen toward your paddle. Each is labeled with a letter, indicating the effect of that power pill. Pills can elongate your paddle, slow the speed of the ball, duplicate the ball three-fold, turn your paddle into a laser paddle, enable your paddle to catch the ball, give you an extra player, and open up a gate that allows you to skip to the next level. Additionally, there are free floating shapes that hover in the game screens which will ricochet your ball. ~ Michael Schwartz/Joan Dykman, All Game Guide