Just like Superman had his Kryptonite and Batman had his fondness for underage boys, the heroes and villains of Heroes (and Villains) all have their own exploitable vulnerabilities.
It's tempting to describe Heroes as "a kind of pretentious X-men" or "X-men with emotional problems" or something, but the truth is that X-men already had all of that. (on Cracked: 6 Superheroes Who Completely Lost Their Shit) So, maybe it's just "X-men without the funny costumes" or "X-men without as much teamwork."
What series creator Tim Kring and his writers seem to have been going for, though, was something more along the lines of "X-Men meets The Matrix." In the first season, there were almost as many Matrix references as there were comic book references. That's kind of a shame when you consider that no one involved in the project had the money, the talent, or the time to put together an even remotely Matrix-esque action sequence.
With the second season (on Cracked: 5 Questions Season Two of Heroes Had Better Fucking Answer), Kring was looking to take the series in a whole new direction, but then fate was all like, "fuck you," and every screenwriter in America went on strike. The plot suffered. (on Cracked: The 5 Most Maddeningly Unresolved TV Plotlines)
Going into season three, the writers made a point of listening to the fans. More precisely, they made a point of slavishly taking nearly every idle fan complaint as a directive handed down by God himself. The script meetings must have been hilarious.
Writer #1: "It looks like most of those characters we introduced last season haven't really caught on with the fans."
Writer #2: "I see what you're saying. We have to kill every single character that was introduced last season!"
Writer #1: "What? No. That's stupid."
Writer #3: "IT'S THE ONLY WAY TO WIN BACK THE FANS! THEY DEMAND A SACRIFICE IN BLOOD!"
Fans also complained that the second season moved a little too slow, so the writers responded by picking up the pace. Then, they tied the pace to their backs and jumped out the fucking window with it. The third season was a rip-roaring thrillride of non-stop confrontations, plot twists, and cheesy action sequences. The thing is, though, stories don't actually work like that. It's supposed to be a story arc, not a story plateau.
Ratings dropped. People were fired. It was a fucking mess. But, hey, the post-firing episodes were an amazing improvement, by which we mean that they were sort of okay, or at least not as brain-fuckingly retarded.
So far, the fourth season has been entirely devoted to absolutely nothing happening.