LumberingTroll: it does have options similar to traditional DRM, in which steam would have to be installed and running in order to play the game, we wouldn't use that.
lowyhong: Will I be able to download it from Steam and copy the files to a thumbdrive to play without the client?
Yeah, that's what he seems to be intimating, if he does this and is using Steam as a storefront only, then I think it's fair to say he kept his promise. If not he broke it.
I didn't back this, but given his general attitude I don't hold much hope for you guys. In fairness to him, he's likely finding out what a bitch developing an actual release quality game is (as any end user software development is). I wouldn't be surprised if someone found, after their KS, that it was either leverage Steamworks to get promised functionality in or the project fails. If that's the case, I could sort of understand, but such a situation should be communicated with apology and humility... not flippancy and annoyance.
Seriously, given he could hand 500 bucks to a cracker to crack the Steam DRM parts back out of his game (with his help) and provide the result to his backers, then sell only on Steam, I'm not sure what his hangup is.