Kooky Klimber

Author's notes:


Game Play


The gameplay for Kooky Klimber is simple – reach the top of the building by avoiding getting your hands caught in closing windows, while also being careful not to get hit by dropped dumbbells and flower pots. To move up a flight of the building, you must pull back on the joystick and then push forward. You can move left and right to dodge falling objects and closing windows by pushing left and right on the joystick. Once you near the top of the building, the objects quit falling because there are no windows above you from which they would fall. Once you reach the top of the building, you start all over at the bottom of the next building, represented in a different color. You continue the game until all of your three Kooky Klimbers are knocked off the building.


Development Notes


Kooky Klimber was based on the Nichibutsu arcade game called Crazy Climber. The A/W/A team played Crazy Climber at Mickey Rats arcade in downtown Ann Arbor, and loved the daredevil theme of climbing up a building. Crazy Climber featured comic-book-style cartoonish characters, catchy background music, and it was one of the first games that used a digitized voice (“Go For It!”). After reading about vertical scrolling and Display List modification techniques for the Atari computers, the A/W/A decided that this would be the ideal game to copy. Many “ripoff” clones in the 1980’s used titles very similar to the original game, but with enough differences to presumably avoid lawsuits. For their Crazy Climber knockoff, the A/W/A team thought of the clever title of Kooky Klimber which also a “double K” alliteration. The game makes use of the Player/Missile graphics available in the Atari. The title character was one obvious Player/Missile graphic, then there were other Player/Missile Graphics in the form of items that fell from above, including a flower pot and a spinning dumbbell, all patterned after the original game.


The main player was animated so that he moved his arms and legs up and down as he climbed up the building. These animations were fairly easy to sketch out in the 8x8 character limitation. The A/W/A team used graph paper to draw the characters, then drew the 8-bit binary multipliers in the columns above and wrote the 0-255 value corresponding to each row of the character on the right side of the character. Each of the 4 frames in the animation was drawn out, and repeatedly re-written in the Player 0 character map as the animation sequence took place with each move up the building. The body of the character “scrunched”, or “compressed,” as the character animated, and this was actually an unintended bug due to incorrect positioning of the animations and a missing a row of the data when it was programmed. Since it actually looked pretty good, the A/W/A team kept it in the animation sequence. There was also a nifty 4-note sound effect that corresponded with the animation sequence with each move up the building.



Each level had opening and closing windows that were modified in the Atari’s Display List. The timing of the windows opening and closing was perfect for gameplay, and therefore made a really challenging game. When the windows closed on the hands of Kooky Klimber, or he was hit by a flower pot or dumbbell, he fell to the bottom of the building. The scrolling for this effect was really quick, and often Display List glitches could be seen because Atari BASIC couldn’t handle the modifications to the memory fast enough. The glitch was something like a quick jerking of the screen, that would only last 1/60th of a second, but it could be seen occasionally. The vertical scrolling of the building was implemented as rough scrolling (8 bits at a time) as opposed to fine scrolling (1 bit at a time). The glitch occurred when the graphics scrolled though a “page” of memory (256 bytes). To modify the Display List to do this required changing two bytes (most significant byte (MSB) and least significant byte (LSB)) on the 8-bit computer to address the 65536 (2^16) memory space. These changes were supposed to be done during the vertical blank time when there was just enough time to write a little bit of code during the vertical blank interrupt (VBI). When done in BASIC outside of the VBI, each byte (MSB and LSB) needed to be modified sequentially and that caused the glitch because for a brief period, the memory location being pointed to was not correct.


Once Kooky Klimber reaches the top of the building, the score is displayed on a separate screen, and he starts at the bottom of the next level. The next building is implemented as a different color, the windows open and close at a faster rate, and the items fall from the top of the screen faster as well. There really wasn’t room to display the score and lives remaining on the main scrolling screen, so it was only displayed at the end of each building and at the end of the game. Another problem was that it was difficult to mix text and graphics, so a display list modification would have been necessary to position a line of text, and that would have been difficult to implement.


The falling flower pots and dumbbells were very well done. The dumbbells rotated as they tumbled from the sky. Also, with each vertical move of Kooky Klimber, the falling objects moved in tandem with the building. In other words, instead of falling at a rate of speed independent of the moving building, as the building scrolled down, the falling objects moved quicker in relation to the sky so they would move with building at the same rate. This extra level of realism took extra time to implement, and many arcade games even ignore these kinds of details. Every once in a while, the falling objects had a glitch where they were distorted. Obviously, it was some sort of memory over-write that may have occurred when Kooky Klimber was loaded after another program, but the bug was never fixed. It was rare, but occasionally a misshapen falling object comes on the screen.


Kooky Klimber was the first game that was sold by the A/W/A team. They sent a long technical write-up describing the game’s instructions and programming techniques along with a cassette of the BASIC listing to COMPUTE! Magazine. A few weeks later, they received a letter from the editor offering $400 for the rights to publish the games. The A/W/A was absolutely thrilled that they got paid for a game they loved writing and playing initially for only themselves. Unfortunately, the game was never published by COMPUTE!