i) Dynamic DSP graph reconfiguration. The ability to seamlessly (no clicks or
dropouts) create and destroy graph elements and garbage collect on the fly.

ii) Through a supported (official and documented) message passing system

iii) Intermediate object manager layer (Python?) (as suggested Pd objects) to
create, coordinate, destroy sound objects.

vi) Some properly optimised reverb and spacialisation (5.1 etc) objs (as C externs)

SuperCollider pretty much covers this list and it seems well suited for working with a game.