If you're a fan of the earlier entries in the HoMM series, this is everything you could want from the genre. The changes that stand out most are the way your towns are modular and expand on the map, and the spellbook no longer being left to random chance. The former ends up meaning that you can focus a settlement on producing more of what you need for your playstyle while foregoing options that don't fit, and that a weaker army can still harass a fortified settlement by pillaging whatever has been built around it. The latter means that your use of magic ends up being more of a strategic choice based on what units you decide to focus on, since the points you have to cast spells are generated by the units in your army.
An interesting story and characters hamstrung by falling into the classic trap of devs deciding that all the fun toys you've gotten used to in the core game are not the way they want you to play their new content. Wanna sneak by those cams with optical camo and the Kiroshis specifically made to nerf cams? Well no, that's not the way we intended for you to get by this so it just flat out doesn't work. You want to dash over the trap door we've set for you? Unless you disarmed it like we wanted you to, you're locked in place while it dumps you. Want to use Sandevistan or Kerenzikov in vehicle contracts? You're not allowed. I'm still grinding my way through it and finding things to appreciate, but I don't know if I would be if it weren't for the main game outside of it.
No matter what I did, from trying the fan made patch to installing and running in administrator and/or compatibility and/or windowed mode to making it large address aware made this game playable past the third episode of the first chapter. I say disappointing because it's a very charming game that fills a sorely underserved niche in a unique way but if it's literally unplayable then it can't be recommended.
It runs smoothly and has simple and intuitive controls. The battles have plenty of depth and variety to keep things fresh and interesting in their own right and the campaign mode really gives you the feeling of driving those dirty, carpetbagging Yankees back up north where they belong. The game is exactly what the description, screenshots, and videos make it out to be.