Lost Echo: Resonance is the upcoming free epilogue to Lost Echo. Here are some early screenshots we have released on twitter in the past.
Admittedly the graphics are much better than these screenshots now, but they still are indicative of how the free epilogue will look.
Since the polycount and shader complexity is increased, I don't think we can hit 60fps on old devices (iPhone 4 and maybe the low memory Windows Phones). We'll probably target 30 for that and 60 for everything else. We're doing parallax corrected reflections on some shaders (that's on Unity 4, our own shader), but it's also quite expensive on really old devices.
We'll also want to enable things like motion blur for the really new devices. We're need to experiment more with the settings for good performance everywhere. In general, all versions will look very similar.