Playing it
Kiwibass reads articulation from the notes themselves, so a bassline played with some care shapes itself. None of this has a control; it is how the voice answers.
One voice
Kiwibass is monophonic. A new note takes over from the one sounding.
Velocity
Velocity moves four things at once. A softer note is quieter, duller, cleaner and less punchy together, the way a struck string behaves. A hard note is louder, brighter, more driven and drops further into its pitch.
A change of velocity between tied notes slides rather than steps.
Note length
How long a note is held sets how long it rings after you let go. A short note stops short, a held one fades out more slowly. Past about a second of holding, the release stops growing.
Overlapping notes
With Legato on in the Voice panel, a note played while the previous one is still held ties to it: no new attack, and the pitch slides by the Glide time. With Legato off, every note is struck anew and lands on its pitch.
A note played during the previous one's release, after you let go, is struck anew either way. What decides a tie is whether a key is still held.
Pitch
Higher notes play a little more plucked than lower ones on the same patch, so a line that climbs stays tight at the top.
The low end
The sub is a mono sine below the crossover, and Spread, Drive and Tone act only on the layer above it. No setting widens or distorts the sub, so a patch cannot phase-cancel its own bass.