I see my review was not helpful, so I'll try to revise it with some additional knowledge and assistance. This is not intended to be the manual. In fact it has a manual, so please read that.
This synth has a very unique sound akin to FM. It uses Phase Distortion Synthesis: http://en.wikipedia.org/wiki/Phase_distortion_synthesis.
2 oscillators (DCO)
There are 2 waveforms per DCO.
You can draw the pitch envelope.
You can switch them on and off.
You can set the octave for the synth.
2 LFOs, one for each DCO.
2 filters (DCW), one for each DCO.
2 amps (DCA), one for each DCO.
There is a global section for polyphony, pitch bend, glide.
There is a reverb and delay.
Line Select allows you to select both, one or the other, or 1+1 which modulates the oscillator against itself (surprisingly there is not a 2+2).
The DCOs are combined by a Detune, Modulation, and Output section
There are several ring mod algorithms that are a lot of fun to work with.
There is a noise generator on the Modulation section.
How the envelopes work:
You can set up to 16 stages.
Sus controls which point is the sustain.
If you have Rpt off, it will sustain only on one point and not fluctuate at all.
If you have Rpt on (sus becomes end), it will loop through the repeat section as the sustain.
If you want a standard ADSR, give it steps 3, sus 2.
It's hard to see, but there is a little bar you can click at the top of the envelope generator that will give you a drop down menu with some helpful options.
After a lot of experimentation, I have found that this synth excels at filling the high end of the frequency spectrum, in a way that few other synths can. It is great for glitchy electronic sounds and retro FM type pads and electric pianos, and yes... you can do dubstep growl basses with it. You can get a lot of the sounds you would expect out of a 2 operator FM synth, but with the ring mod algorithms you can get a lot more out of it.
It's not the easiest to learn or use, but it's worth your time.
This synth sounds really good, but the CPU can be a limiting factor. The limited oscillator section (originally designed to be hardware) reminds me of the Arp 2600 a little bit, and there are some flexible routing options that also remind me of the Arp 2600. It has a weird sounding duophonic mode where the oscillators are controlled independently.
Free of charge.
Great sound quality.
Duophonic mode is fairly unusual for most synth architecture.
Flexible ring modulation.
High CPU usage (especially when using the Voice Stack feature).
This synth fills a void where a part chiptune, part semi-modular synth is needed. You can create complex tones by adjusting the ADSR envelopes which operate independently of each other. Overall pretty cool synth and fun to play with.
An otherwise simple 2 oscillator synth, but with lots of assignable modulation sources. Lots of hover help messages.
Great choice for dubstep or electro house genres. You can add plenty of grit with the phase distortion and waveshaper, and then modulate those with an LFO or ADSR. It's one of the few synths that can approximate the sounds of Massive without using wavetable synthesis. Lots of filter models.
It's free so do yourself a favor and play around with this synth, or at least check out the presets to see what this bad boy is capable of. It's not capable of everything, but it certainly has a unique sound a personality to it.