These apps cosistently rank as the highest rated features of each course they are featured in. As the sole designer, artist and programmer for these applications.
The UDK made doing each of these MUCH easier due to the more powerful toolset. in fact, it was really hard in some cases to not completely redo everything to take proper advantage of the UDK.
For example, the terrains are 25,000 polys+ each and have multiple morph targets. Transforming them is hugely expensive thanks to all the pretty rendering tricks available :D
However, due to the tiny budget available, I was only really able to redo the rip-rap stones as a simple plane with fancy mapping applied to mimic the geometry rocks used previously.