In the old plus, if I managed to roast a guy before his seekers hit me, they would not kill me most of the times. I could jump on them if he's roasted. Now they do. I'm not sure if it counts as a bug, but it makes for very different gameplay.

We're happy to hear that, given that the most recent update is entirely dedicated to changing how bullets work. You can read about the contents of the update in J2O news or the JJ2+ readme.