A set of simple generative sound engines using OnAudioFilterRead() for Unity3D. I borrowed pretty heavily from JZito's Unity Synthesizer in C Sharp to get started, and recommend checking that repository out for a more modular implementation. Ultimately I reorganized things for myself so each engine is pretty self contained.
The scripts inside of Scripts/SoundEngines/ are the fun part. Add one of those to a gameObject along with an AudioSource and you are in business. You will need to make a script that calls the KeyOn() method to activate the sounds. The inspectors for these are very minimal, but there should be plenty there to play with and extend. The included scene shows some ways the audio could interact with a gameObject.
Hopefully the 3 demo scenes will give an idea on how to integrate these sound engines in fun ways.
A quirky 2-op FM design with feedback on both the modulator and the carrier. Makes some good growly sounds.
Simple loopy sample player/synth loosely inspired by the Volca Sample in loop mode
2-osc subtractive square+triangle synth design with a Moog-style VCF and waveshaping distortion
Basic triangle LFO class can be added using "new pxLFO()" in your synth code.
Basic AD/ASR envelope generator class. Can be used as "new pxLope()"