Uploaded August 2022 | Updated September 2026, 2 weeks ago
After a quick test by James Earl O'Brien from ZeroPage Homebrew (youtube.com/channel/UCH4A1gfZKj3SWBBKz9-wqjw) on hardware, it was determined that the graphics glitch was not an emulation issue. The glitch seemed to occur on occasion with the balloon boy and the life counters where the top scan line of the sprite would shift to the right by about 20 pixels or so.
My best guess was that this was an issue with the DPC+ kernel when I would reposition virtual sprites too close to each other. As a test I reduced the size of the toolbox by one scan line and shifted the spawning of the balloons up by one scanline and it seemed to have resolved the issue. If you watch previous videos, when the toolbox appeared was when the top of the life counter would shift. Same for when a balloon would appear but since the balloons constantly move up it was less pronounced and if your focus was on the balloons you may have missed seeing the balloon boy glitch out.
I had also started to toy with a couple added difficulty progression features that I had mused on the forums. While not in this video I had implemented a change in direction for the balloons midscreen. I did not want a random shift to prevent the balloons from getting stuck in a cycle where they were always out of reach so if they hit a range between several pixels of the middle utility pole at a specified time the particular balloon will shift. In tests this happened not as often as say the barrels down the ladders in Donkey Kong so hopefully this would just be a minor gameplay variation offer.
My next test will be to add more balloons which may be fun but I think to avoid it being to crazy I may limit it to one or two of the balloons and to only two virtual sprites because it would require a whole new block of balloon movement since they currently bounce back and forth at the screen edge but if I use virtual sprites I will need to have the coordinates be determined by which sprite is grabbed. I have an idea how to implement it but require a small chunk of time to get it all out.
After a quick test by James Earl O'Brien from ZeroPage Homebrew (youtube.com/channel/UCH4A1gfZKj3SWBBKz9-wqjw) on hardware, it was determined that the graphics glitch was not an emulation issue. The glitch seemed to occur on occasion with the balloon boy and the life counters where the top scan line of the sprite would shift to the right by about 20 pixels or so.
My best guess was that this was an issue with the DPC+ kernel when I would reposition virtual sprites too close to each other. As a test I reduced the size of the toolbox by one scan line and shifted the spawning of the balloons up by one scanline and it seemed to have resolved the issue. If you watch previous videos, when the toolbox appeared was when the top of the life counter would shift. Same for when a balloon would appear but since the balloons constantly move up it was less pronounced and if your focus was on the balloons you may have missed seeing the balloon boy glitch out.
I had also started to toy with a couple added difficulty progression features that I had mused on the forums. While not in this video I had implemented a change in direction for the balloons midscreen. I did not want a random shift to prevent the balloons from getting stuck in a cycle where they were always out of reach so if they hit a range between several pixels of the middle utility pole at a specified time the particular balloon will shift. In tests this happened not as often as say the barrels down the ladders in Donkey Kong so hopefully this would just be a minor gameplay variation offer.
My next test will be to add more balloons which may be fun but I think to avoid it being to crazy I may limit it to one or two of the balloons and to only two virtual sprites because it would require a whole new block of balloon movement since they currently bounce back and forth at the screen edge but if I use virtual sprites I will need to have the coordinates be determined by which sprite is grabbed. I have an idea how to implement it but require a small chunk of time to get it all out.
