I've been learning to mod the game Dragon Age Origins so I've been learning it's toolset. So far I'm really impressed with how powerful it is.
However it has a lot of big limitations. The biggest being all the terrain in an outdoor level has to be part of a single mesh. Bioware seemingly figured out tricks with it to make some of the more visually distinct levels. Like the Fade levels for instance I discovered that all Bioware did was put a pure black water mesh down to hide the rest of the terrain and the horizon line.
The cutscene editor is extremely powerful and something I plan on taking full advantage of eventually. Machinima back in the day when they made actual machinima partnered with Bioware to make this machinima series using the toolset. Which is found here
https://youtu.be/8vbs_FaXNyI