I first realized a 4 screen Basic version could probably work when I joined here and the batari Basic DPC+ kernel had just released, allowing 10 single line, multi-colored sprites and single line playfields. So it all flickers badly at the top, it's fun and on the ancient 2600! Carefully planning the fact that Playfield color changes have to be every other line. I was great with layout, graphics and music (music and sounds are hard and always harsh), but I did way better than the 7800's version sound which uses the same sound chip and it so terrible, most won't play it or play it with the sound off!
After shelving it for a bit, I had learned enough to get your player to climb and fall in Level 4. I probably would have had sliding fireballs back and forth like the Coleco version, and a score, but had no clue how to have both a score and the countdown timer.
It would have been a nice batari Basic game from me alone, but it became more than I ever planned when Byte Knight wanted to see it finished and he worked on game logic, along with Rev Eng helping and squashing some bB bugs and adding to bB, and Bogax who can turn simple code into data sets and his optimization teaching. All of a sudden fireballs were roaming randomly all over, then Level 1 had barrels randomly choosing to go down ladders, and hammers (which I had planned to just be a simple yardstick (missile object). Later on we were using more cycles than allowed for a stable screen, so it was suggested a simple batari Basic hack would give more overscan for processing, another hack would take out the new, unneeded scrolling for 200 some bytes in Bank 1, then an idea that if the screen was a few scanlines taller, the flicker at the top could reduced if the bottom of The Lady object were 7 scanlines away from the barrels. Making The Lady shorter and adding scanlines was super easy thanks to Rev Eng's knowledge.
if I remember correctly, the pie/cement factory was next and straightforward to code, except for the single double triple sprite juggling so they appear like the arcade, but I again ended up amazed with sliding Kong back and forth, and how the barrel spits out fireballs. It is a quite simple level in the arcade to finish playing which is probably why the American released put it way out on the 7th board.
The layout of the elevators just came to me and I had it done out in a single day. Programming the player to climb, jump and ride the elevators was another extremely hard thing to program for Byte Knight, and you can still do some jumps that should be safe that end up in falling. A ladder was moved and a section removed to make it easier to program and harder to complete, but the arcade's bypass jump off elevator 2 to a platform near the top remarkably works, if timed just right. Insert another amazing, I can't believe it!
With so much that had to be changed or cut out that is in the real arcade game, it still, to me, plays remarkably close to the arcade game, all in 20K of coding and 4K of graphics, with the rest of the 32K being batari Basic and DPC+ kernel. Nearly filled all ROM space up. No "cycles" or "sprites" left for Level 1 fireballs or blue throw barrels or bonus collecting items (bonus items would cause a flicker that even I refuse to play), and no rebounding off the sides, and more player animation would have been fun. No sprites left for bonus items in the rivet Level 4 (too much flicker) and it could be done if the player flickered, but that was a thing I wanted - no flicker transparent player. No flicker Player 0 and the no flicker Playfield with everything else being reused Player 1 is what "just works best" for a complex game like this in batari Basic.