the green Grundle, and the red Rhindlethat protect or flee from various items and attack the player's avatar. An enemy bat can roam the kingdom freely, carrying an item or a dragon around; the bat was to be named Knubberrub but the name is not in the manual. The bat's two states are agitation and non-agitation. When in the agitated state, the bat will either pick up or swap what it currently carries with an object in the present room, eventually returning to the non-agitated state where it will not pick up an object. The bat continues to fly around even offscreen, swapping objects. The player's avatar is a simple square shape that can move within and between rooms, each represented by a single screen. Helpful objects include keys that open the castles, a magnet that pulls items towards the player, a magic bridge that the player can use to cross certain obstacles, and a sword which can be used to defeat the dragons. The player may only carry one object at a time. If eaten by a dragon, the player can then opt to resurrect the dead avatar instead of completely restarting the game. The avatar reappears at the Golden Castle and all objects remain at their latest location, but all slain dragons are resurrected. The ability to resurrect the avatar without resetting the entire game is considered one of the earliest examples of a "continue game" option in video games. The game offers three different skill levels. Level 1 is the easiest, as it uses a simplified room layout and doesn't include the White Castle, bat, Rhindle, nor invisible mazes. Level 2 is the full version of the game, with the various objects appearing in set positions at the start. Level 3 is similar to Level 2, but the location of the objects is randomized for a greater challenge. The player can use the difficulty switches on the Atari 2600 to further control the game's difficulty; one switch controls the dragons' bite speed, and one causes them to flee when the player carries the sword. Development Adventure was designed and programmed by Atari employee Warren Robinett, and published by Atari, Inc. At the time, Atari programmers were generally given full control on the creative direction and development cycle for their games, and this required them to plan for their next game as they neared completion of their current