First off, I'd like to say that while I like the Untold RPG, it may not be for everyone. That being said, anybody interested in steampunk should check this out, as it's mostly setting info, with very little in the way of Untold-specific rules.
Steamfunk introduces us to the world of Daedalus, an alternate reality where a number individuals (known collectively as Titans) made discoveries that led to the creation of "Civilization Engines" which power cities with steam. Unfortunately, it's been several centuries since the Titans have died, taking the secrets of the Civilization Engines with them.
Now high society literally lives above the lower class, as each city is divided by a separator plate that traps most of the steam below.
The authors tap real-world locations and historical figures as inspiration, along with the works of people like Jules Verne.
The moon of Daedalus has been recently open to exploration (a lush jungle world) via "cannon travel", and the natives (animal-like beings known as Ma'hina) are not happy about it.
"Automatics" (clockwork beings) also exist, created by one of the Titans. They now serve as administrators and foreman, which often causes conflict with the humans whose jobs they've taken.
In addition, there's another race, called the Gatekeepers (who are related to the Ma'hina) that are trying to keep an ancient evil buried beneath the world. Unfortunately, expansion of the steam pipes for the Civilization Engines are getting close to breaching the barriers...
Oh, and the Civilization Engines are slowly failing...
All in all, a fascinating setting!
It could fairly easily be converted to something like Mutants and Masterminds, or even Pathfinder (with the upcoming release of the Advanced Race Guide).
For instance, the Tradesmen and Upper Class are just humans. The Ma'hina and Gatekeepers are magical beasts (yes, I said magic--which takes the form of crystals or talismans that access spells). The Automatics (Administrators and Foremen) are constructs (although living constructs like Eberron's warforged would do nicely).
Oh, and the Deep Lords bring to mind Cthulu and could easily be represented by fiends and other evil outsiders!
For $5, it's actually quite a good deal! Give it a look!