Babylon is a strange mix. It is quite a capable synth with most of the controls on a single page. It sounds pretty good, too, but somehow it fails to inspire. I think a lot of the problem is with the massive load of presets it ships with. Looking at their names and hearing how little variation there seems to be going from one to the next, you get the feeling they were made by some automated process that went through and moved one parameter by a fixed amount and then saved that as the next preset. Even the Demo bank, which tries to show a broader range of sounds, has too many soft sinewave based patches that could be anything. But if you listen to different presets randomly, you start to get a better idea of what Babylon can do.
It's a 3 osc synth with per-osc unison, so it can sound massive. You can cross-modulate Osc 1 and 2 with Osc 3 for FM, Ring and Amplitude mod effects. If Osc 3 isn't being used and you switch on one of the cross-mod modes, it turns green (instead of blue) so you know it's in use but not making any sound. It's a nice touch. Another nice visual touch is the display to show you how the unison voices are being allocated. It's something that's tricky to visualise but the display shows you where/how unison voices are being added. You also get a subtle glow in the highlight areas of the GUI when your levels peak, which is kinda cool (can be turned down or off if you don't like it).
The filter is a mixed bag. You get 5 different filter types - Low Pass, Band Pass, High Pass, Notch and Peak. The Peak filter is something a bit different and much more usable than I expected it to be. For both the Notch and Peak filters, the Resonance knob controls the Q. The filter also includes an effect knob and you can choose from various forms of distortion/saturation/bit reduction to give the filter some extra character/bite. It works very well. Where the filter falls down is that the modulation depth of the dedicated filter ADSR envelope is not enough to completely open the filter. The Env Mod at 100 (maximum) only opens the filter to about the same level as turning the cutoff to 30. Adding one of the Mod Envelopes to Cutoff in the Mod Matrix doesn't help as the combined values seem to be multiplied (in the range -1 to +1), not added. The filter visualisation is static, it would be nice to see it move with the modulation applied to it.
As well as dedicated filter and amp envelopes, there are two LFO and two Mod Envelopes to use in the 8 slot Mod Matrix. The problem is that, like the Filter Env, they all lack modulation depth, which severely hampers the synth overall. It's a real shame because it would be an easy fix and it would make the synth way more useful. If the dev could fix this problem, Babylon would be a really good synth to have for all kinds of situations. As it is, for everything that you might like about it, you are bound to find something that's a bit of a disappointment. For the $9 I paid for it, I am happy enough but I can't see the value in it at full price, I'm afraid.