Bubble Bobble also featuring Rainbow Islands

In the game, each player controls one of the two Bubble Dragons, Bub and Bob. The player can move along platforms, as well as jump from one platform to that above, or to the side, in a similar way to most platform games. The player can also blow bubbles. These can trap enemies, who are defeated if the bubble is then burst by the player's spiny back. The bubbles also float for a time before bursting, and can be jumped on, allowing access to otherwise inaccessible areas. Players progress to the next level once all enemies on the current level are defeated. Enemies turn "angry" – becoming pink-colored and moving faster – if they are the last enemy remaining, escape from a bubble after being left too long, or a certain amount of time has been spent on the current level. After a further time limit expires, an additional invincible enemy appears for each player, actively chasing them using only vertical and horizontal movements. These do not need to be defeated to complete the level, but disappear once a player's life is lost. Contact with an enemy is deadly, resulting in the loss of a life.