Here's update #4 to fixing DKjr, just unzip and copy these files into the dkongjre folder in the roms directory.
This update is a lot more extensive than before. The more I went through the code, the more apparent the broken things became. So I decided that it's OK to make wider changes... whatever it's going to take to fix.
Sometimes there was code where I can see the intended functionality, even if it doesn't actually *work*. Stuff like the level 1 vines screen supposed to have 3 red snapjaws, level 2 is supposed to have 4 red snapjaws, level 3+ have 5... Well, 4 never happens because the routine that does the check happens to trash the value of the registers it's testing... Anyway, so in cases like that, I tried to implement their intention.
There's some evidence that they intended blue snapjaws and blue sparks to have more function in their AI - the blue snapjaws check for the bottoms of vines, for instance.. so I think they were intended to do more than just fly straight down into the water. But whatever, that's too much a change for now - but Jr Remix will expand the AI functions.
There's a lot of little details fixed, like how platform & vine detection and handling is done.. Generally, things most people won't even notice.. unless maybe you go back to the normal DKjr and then you'll notice something isn't going quite right.
I also tried to balance the difficulty. I fixed some of the internal difficulty functionality that was hacked up and made it advance more gracefully and affect things in the game in a reasonable way. Hopefully that makes the difficulty increase smoothly between levels 1 and 5.
I *think* I got things pretty good now. A casual player probably has a chance at surviving past level 3.
Anyway, give it a go and let me know if the game is more fair and less frustrating. This will be the code that is the base for DKjr Remix.