Ah, so. It has arrived. Heroes of Might and Magic IV. There are many different opinions on the game, and even more different ways of looking at it. I feel that it is both important and useful to start by forgetting everything you know about Heroes I-III. While it's true that there are many excellent aspects of those games that did not make it into Heroes IV, perhaps to the detriment of the project, it is most important to avoid being fixated on Heroes I-III and instead to look at Heroes IV as a new product. In short, as we look at Heroes IV, and as you hopefully go out and buy it, try to start with an open mind.
Other reviews, in depth reporting from major game sites, and official game documentation explain a lot about the basics of how the game works, so I'm not going to go into too much detail here. Instead, I'm going to talk about towns and creatures, heroes, combat, and game play. I had planned to write sections on the map editor and on stability, but unfortunately I have not experimented with the editor yet and fortunately most stability issues seem to have been resolved.
As a multiplayer patch is expected soon, I won't address multiplayer issues here.
Towns and Creatures
The new town building schemes in Heroes IV are both exciting and excellent. Borrowing an innovation from Disciples, at each of the three highest levels of creature generation you must choose to build only one of two possible generators in any given town. The strategic possibilities are vast. In the Haven town, for instance, with squires, crossbowmen, pikemen/ballistae, monks/crusaders, and angels/champions you can build an almost all shooter army, an almost all walker army (and the combination of pikemen, crusaders, and champions makes a VERY impressive group of groundpounders), or any one of several combinations. Other towns may not be as perfectly balanced as the Haven, but you get the idea.
The creature selection is less wide than in Heroes III, but I see no reason to complain. Yes, there are no upgrades, but each and every creature now enjoys some sort of special attack. While it's true that some are more useful than others (it is especially nice that many spell casting creatures now come with limited spell books instead of a single spell), it makes it worthwhile to try out every possible creature combination in any given town, in order to try every creature and see how each creature compliments every other creature in its town.
On the subject of balance, of course it is not perfect. It never is. However, it seems to me that with a competent commander, any town can perform nearly as well as any other, or at least close enough that it is fun to play as any town, rather than overwhelming. Of particular use in terms of balancing creature strengths are adjustments to individual growth rates. (Incidentally, creatures are no longer generated as a block every week. Instead they are evenly distributed each day.) Although always present in Heroes games, this is especially apparent with the new creature choices, as you are often presented with a question of quality or quantity.
Neutral creatures remain in Heroes IV, but now they have an alignment, making them 'unable to be hired in town' (excepting the use of a creature portal) rather than truly 'neutral.' This is an excellent change because it makes it so that spells that affect a certain alignment can affect neutrals as well.
Ah, heroes. The namesake of the game. They've come a long way. There are three notable changes to heroes in Heroes IV. First, gone are the individualized heroes. Yes, they were cool. But honestly, I only found heroes like Ivor and Solmyr to be of much use. It's a loss, but not a large one.
Second, there is a very exciting (not to mention vast) new secondary skill tree with five levels of expertise instead of just three and requirements to advance skills. Again, refer to documentation for details, but I imagine that you could play for a very long time without creating two identical heroes. Or, if you find a setup you like, you can always build the same hero.
Finally, the grand finale, heroes in combat! This is a very substantial change from any previous Heroes game, and it too has some controversy about it. My opinion is that it adds a lot to the early game, and has very little impact on the end game. In the early game, it is now incredibly important to protect and nurture heroes as they slowly begin to level from their starting position of world-class wimp. Sure, they have more hit points than your average sprite, but heroes are very low impact until a little later, maybe level 4 or 5. But in the endgame, wow!
As in previous games, spell-casting heroes tear through almost any opposition. The difference now is that heroes are actually participating in combat and so they can also mow down armies with physical attacks. At last, a hero's breastplate actually improves the hero. Combat skills are now incredibly important, and New World Computing has emphasized this by making it by far the most common secondary skill offered.
Of course, there are balancing limitations. Now, Heroes can only cast spells when it is their turn in combat, and of course, they can be killed. But do not fear! Your Heroes can be resurrected by any town or sanctuary. Let me close this section by saying that it is incredibly cool to have an army of seven heroes. It's like a real role-playing game! (Complete with very slow leveling as the experience is divided between them.)
This has mostly been covered above, but combat in Heroes IV is essentially the same as in previous games. Other than the role of Heroes, the largest difference is in the new isometric angle and the square instead of hex-based grid. The isometric angle is a little weird, because it creates dead space behind each army. Nice for retreating, but you tend to get boxed in and, ah, shall we say, fried.
Which brings us to the square grid. The effect of this grid is that creatures now vary in size more than ever before. A blast of dragon breath can only hit one griffin, but if you pack those sprites into the corner too tightly, up to three of them can be roasted at once. Ouch!
Compared to earlier games, Heroes IV has fundamentally familiar game play. There are changes, however. For one, I find it much easier to move around the map, as hero-less armies remove the need for heroes to shuttle back and forth moving troops to the front lines, and caravans make it easy to jump between castles towns and to recruit from flagged structures. This is a great feature, but let's be honest. The fact that caravans are invulnerable makes them just a little too powerful. And it doesn't make any sense. Remote hiring from flagged structures is an excellent idea, but it seems ridiculous for these forces and entire armies hired from towns to vanish from the enemy until they are exactly where their commander wants them.
But let's step back and remember the most important thing about every Heroes game, up to and including Heroes IV. The infamous "one more turn syndrome." It's like a sickness. It will keep you up too late. Odds are that you'll still struggle to work or school in the morning, but then again, maybe not. Let me say right now that if you tend to play games too much, or generally lack self-control; this is not a game for you. If you love Heroes of Might and Magic, or strategy games in general, and you have either an iron will or don't mind being sleepy all day, buy it today!