While I was looking over the ICONS material in preparation for this playtest, it occurred to me that some of the games systems I read cause a flurry of sparks, and some do not. Wild Talents does not, even though I can see where it should; Champions did. What I've heard about AMP doesn't yet, but I haven't read the book(s). Interestingly, Mutants & Masterminds 3rd edition doesn't for me, but 1st did. (Second edition is sort of in the middle.)
ICONS first edition did, and second edition less so.
So I've been trying to figure out why that is, for me. Because this is a very personal thing; I know what makes one person's head light up makes another person go, "Meh."
Part of it is the specificity of the game system. The more generic the game system gets, the more flexible it might be, but the more I really have to get into it before I can say, "Oh, here's something we can exploit." In Champions, I was younger but I would also create characters based on the game system. Oh, this character uses this power, which means he can do this, or he can't do that. System mastery is, I guess, part of that appeal, but there's also the old creativity exercise--it's very hard to describe a wall in an interesting way, but it's easy to describe a brick.
Another part is the setting. Does it have nooks and crannies that I can take advantage of? There's a fine line between Freedom City's plethora of characters who probably render the PCs redundant, and the lack of a setting in ICONS or Supers! but both the latter have implied settings that you can grab onto. (Or not, depending on your tastes.)
Part must be presentation, but I'm not sure how.
Part is creativity. I'm sorry to say it, but a chunk of the problem for Capes, Cowls, and Villains Foul for me is that none of the sample characters grabbed my attention. If they had, maybe I'd have looked deeper into the system and grokked it more fully. I grabbed the first villains book, hoping it would do it for me, and it didn't. Now, that might be rectified if I played a game with someone who knows, but I often have to teach myself these games out of the book.
You can combine the setting and the creativity to get some idea of the core activities, what the world is like. I know that to a large degree, the worlds are superhero worlds, and yet some of them (just like some comics) fall flat for me.