is exactly what we do. We’ve been making landscapes for years using CryEngine 3 and have even made the front page of their CryDev user forums multiple times. You can see CryTek even pimping our work on their engine here: https://twitter/cryengine/status/382527241260769281.
We made the jump to Unreal when we saw the ease of use for actual game development in comparison. During our time using CryEngine though we gained a lot of insight into how to make the most spectacular landscapes we could and eventually decided to use that skill set to release our new work here into the Marketplace for all to use. 