The first licensed arcade game released for a console, Space Invaders was the first million-seller for the Atari VCS, firmly entrenching the system into mainstream America. The game is faithful in both spirit and play mechanics to its coin-op counterpart, but it does have a number of differences. Although there are only 36 invaders per wave (as opposed to 55), 112 game variations, including zigzagging laser bombs, two-player cooperative play, invisible invaders, and moving shields, more than make up for this deficiency. The home version doesn't look exactly like the original, but it does have appealing graphics, relatively faithful sound effects and excellent gameplay.