SteamCraft is a wonderful game for its purpose, though it is not entirely without its flaws.
It manages to create a great framework for adventures. The rules are relatively simple and easy to grasp, plus they're not so incredibly boring or predictable you may as well skip rolling for stuff. It's well-written and laced with flavor and other things, though it doesn't get too heavy with this to the point of bogging things down.
On the other hand, there are some major issues. Maybe it's just on my end, but text that has a picture bumping into it (even the transparent areas around it) winds up turning out incredibly pixelated. I'm not sure what causes these issues-all the other PDF's I've tested work fine, even things I've thrown together explicitly to test this seem to have no result, so I'm thinking it's an error with the software on their end; it's not a gamebreaker but it's a little annoying. There's several typos littered throughout the document, which could be a turn-off for some.
Ultimately, my largest gripe with this game is its price-its system is pretty simple and it'd be none too difficult to create a homebrew system that could do everything contained within (though to be totally honest, percentile-based systems have very little room to stand out without becoming gimmicky; which means you could say this about a lot of things) and it could stand a couple more layers of polish and revisions to really command a $20 price.
[4 of 5 Stars!]