Ok I have to chime in to say that Dungeon Defenders is one of my biggest disappointment in gaming (bought it long ago, twice because of steam nonsense).
The concept is fun at the beginning (even more so with friends), but the game mechanics have a major flaw ; you allocate stat points on your hero when you level up, but when you start the 'supposedly' late harde rpart, those points doesn't matter at all because you are expected to have grind (grand? grund?) stuff that with stats that completely override the character development.
Bottom line : behind a nice concept lurks a grind heavy game that is a complete mess character-development wise. In my experience, it's one of those games that in hindsight feel like a complete and utter waste of time (I would have better memories I I had just stopped after 4 hours)
/rant
lepke1979: For these games, do I need to install Steam? Or can I download straight from Humbles site?
Grargar: You can do either; download and play from Humble or activate them on Steam.
I'd check if Dungeon defenders propose the same features with or without steam. I think you won't be able to trade with people playing through steamworks. I didn't play it recently so I am not sure, but this is something to check.