It's funny, but I didn't really start to get into this game until I found a busted combo. It wasn't my first time exploiting it, but you need the right combination of map conditions to make it work, so it wasn't the sort of thing you can do every time.
Here's how it works - there's this spell, called Paragon, that you can use to automatically boost one of your heroes up a level. Very powerful, but it has a downside. Every time you cast it, your leader permanently loses 5 hp. However, there's another spell, not part of your standard arsenal, called Blood Curse, and what it does is cut one of your cities' population in half and then add that amount to your sovereign's hit point total (while making them forever after immune to healing magic). But the only place to find Blood Curse is in a certain wildland, which is not guaranteed to spawn on any particular map.
The combination of the two should be obvious. Within just a few turns I had a whole party of high level heroes and a leader who, if she wasn't quite as high-level as the rest, did at least have more than 200 hit points and some powerful equipment. From that point on, it's basically just a rampage through a randomly generated fantasy world, slaughtering everything I see. Good times.
I think the most surprising thing I've learned over the course of playing this game is that I'm probably done with Fallen Enchantress forever. I still like the game well enough, but, you know, Endless Legend exists. And while Fallen Enchantress has its charms (in particular, the wildlands are just great, better than anything comparable in the genre), it falls down in one fundamental, but unforgivable way - the building and tech trees are completely bland. You more or less want to build every building in every city and your scientific progress is bottlenecked behind one of the three tech trees so alternate strategies aren't particularly viable. I like that there are repeatable technologies at the end of the tree (mainly because I love using stacking bonuses to get incredibly overpowered), but otherwise, it's not balanced very well.
Although, I probably shouldn't lay that entirely at the feet of Fallen Enchantress. The technology race is probably the most problematic part of the 4X genre. I've yet to see a game where bigger civilizations do not get significant advantages to technological growth. This is not only dubious as a gameplay mechanic, leading to runaway snowballing and the game being defacto finished long before the official end date, but it also doesn't reflect reality very well. If it did, China would be a sci-fi wonderland and Luxembourg would be a stone-age backwater.
I think the problem is that in 4X games, information has too much respect for borders. You've got situations where a global superpower is launching spy satellites and exploring the possibility of fusion power and then an otherwise non-hostile, but significantly smaller neighbor has to infiltrate their society with spies just to get ahold of the internal combustion engine. (Not so much a problem with Fallen Enchantress, thanks to the lack of an espionage system, but I'm working towards something here).
What I think is missing is that in the real world, it's not all top-down from some disembodied, immortal authority in the sky. Real civilizations are filled with private citizens that will have their own reasons for taking technologies to new places - maybe they can make money selling high-tech goods, maybe you'd want to offshore educated work to a less developed country's small, but sufficient elite class in order to save on wages, maybe a key discovery is made by someone who learned their field on a student visa and then returned home after graduation. The point is, when people move, they take their ideas with them, but in 4X games, people rarely move.
Maybe it would be unsatisfying if the system were too generous. It might feel like the AI was rubberbanding in order to keep a player from winning too handily. Or maybe it would feel like technology was too much out of the players' control, and thus a key strategic element is left to random chance.
I think, if I were designing a game, I'd probably try and tackle this problem by giving technology a maintenance cost, to represent the societal and infrastructure investments necessary to actually use the technology in a life-changing way (there's an old game Emperor of the Fading Suns that used a similar concept - if you couldn't pay to maintain your labs, you'd lose access to the technology those labs researched). These maintenance costs would be highest for "classified" technologies, ones that gave you enough of a strategic advantage that exclusivity is worth the price. Then, as the cutting edge advance, you could "declassify" your old techs, in which case the maintenance cost would go way down and they would quickly propagate along your established trade routes (possibly even to an enemy, if the two of you share a mutual friend). You might even get an economic bonus if you declassify a powerful technology while it is still new. In this way, trade networks would become the standard technological units and a tiny, well-connected nation might exceed a large, isolated one in technological achievement, because they're reaping a portion of the benefit of their friends' 100 different labs, whereas the empire has to make do with the full output of 50 of their own.
Just a thought. Fallen Enchantress isn't really the sort of game where you'd implement this kind of system anyway. Its fantasy milieu means that your "scientists" are more likely to be eccentric sorcerers, researching dusty old tomes in their lofty towers. Not a great deal of progressive, "information wants to be free," sharing economy ideology to be had there (though that gives me an idea for a fun fictional setting - something like an inverse Shadowrun, where you take a base fantasy setting, but then insert cyberpunk elements and the characters could be down-on-their-luck anarchists who hope to one day get a big score by surreptitiously copying a wizard's spellbook).
Anyway, the point being, before I got distracted, is that the technological race is a key part of any 4X experience, and one that is difficult to implement in a fair and satisfying way, and for as much as I enjoy tromping around in Fallen Enchantress' wilderness, it doesn't really do the essential 4X stuff especially well. So I think 172 hours is going to be my ultimate limit. Farewell, Fallen Enchantress: Legendary Heroes, I was obsessed with you four years ago, but probably never will be again.