Thwocker is an unreleased Activision prototype for the Atari 2600, discovered in 2001 at a thrift shop alongside other prototypes. Developed by Charlie Heath, who also created Reactor, Thwocker has been described as “Joust with musical instruments.” The player controls a little conductor character, resembling a bowling ball, and must bounce around a maze collecting musical notes in the correct order while avoiding various musical instruments that act as enemies.
The controls in Thwocker take some getting used to, as the levels seem to be made of a springy material, causing the conductor to bounce around the screen. Players can control the height of the bounce by pushing the joystick up and down. Pressing the fire button will make the conductor “skip” across the level, and mastering these bouncing techniques is essential to completing the level.
Unfortunately, Thwocker appears to be incomplete, as there is no known way to exit the level. Although it was initially believed that touching the exit square after completing the song would finish the level, this does not seem to be the case. An examination of the game’s code suggests that players must “combine” the two voices of the song after it starts playing to exit the level, possibly by picking up certain objects on the screen. However, it is unclear whether this is actually possible within the game, and Thwocker may remain unwinnable.
(Source: AtariProtos.com)