It's right there in the title: Fantasy General 2. Quite a legacy to compare to, even if this TBS hex wargame is just a free-to-play prologue. It's not a tutorial, more of an appetizer (all the more so considering a new low in marketing, planting Buy Now buttons in the game main menus).
One five-scenarios long mini-campaign is playable, with three alternate mutually exclusive paths along the way (one of which, Lay A Trap, I'll revisit later*). It features three different heroes, which you'll get to upgrade (using an RPG-based skill tree), resource gathering (in a needlessly complicated system: mana and liquid mana - for real?!?) for upgrading/buying units for your army and treasure hunting, wrapped up in a rather generic and bland genre story which hints for more to come (well, duh...). Given the brevity of the whole affair, you can't complete the heroes' skill tree or the units' upgrades, so don't expect to really get into magic on just one walktrhough. There are degrees of difficulty and even achievements, a rather generous offering for a free game.
There's also, though, the unavoidable aforementioned legacy.
This feels more like Fantasy Wars and Elven Legacy than like Fantasy General. Yea, sure, the music and the world map are present and accounted for, the gameplay is somewhat the same, but, unfortunately, the devil's in the details. The single most important difference is that the heroes - your generals, that is - are present on the map. They're just another unit, not so very heroic: they can die (thereby immediately ending your campaign), they waste a turn when using most magic/artifacts, they're not even that immune to the enemy's magic, they have to work out for their mana (even the mage, Ailsa, by far the most versatile choice when it comes to gameplay). Nor are they unique, as some regular units can be upgraded to hero status, spells included. In the original FG, your heroes were you, the player as general, managing and commanding an army, using spells like a god on the battlefield, not mingling with mere mortals. Not so here.
The available units are the same for all heroes and can be upgraded to different classes, meaning a basic infantry unit can become cavalry, archers or even a flyer. This accounts for rather similar armies and a very generic playstyle/strategy. There are differences, such as some heroes not having access to specific types of units, but it's not felt in such a short campaign. (Hiring Mercenaries is not a solution, as they'll be lost at the end of a scenario and, in any case, gold is better spent maintaining your core army). Units will gain XP, but with no overstrength, only bonuses to health and dealt damage. You can't have units in reserve, so as to choose what and when to deploy: it's either the entire army or no go. As a consequence, when there are separate mandatory deployment areas, you'll be forced to split your forces. And you'll do it blindsided, because the maps are completely shrouded in fog: not only enemy units are hidden, but also the entire terrain (at least, the AI doesn't cheat when spotting, not like in, say, OoB). Also, since Prologue is a procedurally generated campaign, maps are randomized which makes absolutely no sense neither in exploration terms, strategic/tactical planning (the actual point of a strategy game), nor in terms of the story. We should be exploring, more or less, the same mythical territory where FG legends were born, not roam some random lanscape.
In short, there's no grandeur and specificity to be found here, only slow grinding, generic gameplay, more reminescent of Order of Battle than of Fantasy General.

To this day, FG, much like Panzer General, remains a template for the TBS genre. All the devs had to do was copy/improve features and keep the core intact. Instead they've gone for what amounts to a "Not-to-do" anthology in game design.
- no Quick Save/Load, no save in deployment phase, no end turn autosave (and there are random after battle rewards...);
- in Iron Maiden mode, there's only one save, automatically rewritten every turn and deleted upon ending the campaign (only one save, between scenarios, rewritten as you progress, would avoid restarting everything from zero);
- confusing World Map: unclear what are and where are located completed scenarios; instead, we get retina-peelers oversized clan/faction icons;
- sketchy/unclear scenario objectives: help the centaurs by slaughtering them?!?; guard the border castles means, in fact, re-take them and plunder them at your heart's desire; *lay a trap for the lizard mage: uh, great, but where and how?
- no turn limit = no urgency in finishing = more time to explore, right?; wrong, since in fact there is a turn counter, the resources on the map dwindling every turn (why?);
- graphics may be pretty, but shouldn't hinder gameplay, like units getting lost in the scenery (spiders in a forest, for instance) or making guesswork when selecting units (choosing between aerial and ground units, for instance);
- aggravating the above and, by far, the most infuriating "feature", there is no Undo Move option;
- more visual clutter: red bars on the enemy's zones of control your unit can reach; simply showing where it can move has worked time and again for countless TBS games, why not here?;
- why put combat predictions in a separate screen from the units locked in combat???;
- in the unit info panel, useless button for the default attack, since that's what the selected unit does anyway;
- a novel concept: adjacent ambush, in which your unit can be ambushed by simply moving next to an enemy-occupied hex (not to mention that the ambushed unit can subsequently proceed with its turn...);
- archers/slingers shooting over impassable mountains... ;
- an attack that kills an enemy unit or forces a retreat automatically makes the attacker advance in the vacated hex... a decision that should be the player's;
- not clear when/why/how certain spells/artifacts work or not (Charm is a prime example: didn't work when units were stacked, didn't work on a clearly-labeled Animal unit; there's an artifact that creates forests, but it doesn't show which hexes will be affected, only where it can be activated);
- last but not least, game is very taxing on the system (unjustifiably so for a TBS imho), overheating being the main symptom.

Having mentioned early the generic story, I'd like to add that even as such it doesn't make much sense. Why does Hrazzkar moves from lizard shovels, his natural habitat, to living behind fortified walls in the last scenario? Later on, your units can waltz right in through said walls, making it quite unclear as to what sort of protection was provided in the first place. Finally, why would the Empire worry about a small disturbance in the Fareach, a very distant area from their territory (makes sense for the other faction, clan Baileach, to be concerned about it, since it's right at their doorstep)?

Is anything from the above game-breaking? No - and you can learn to live with or around most of these problems. So, by all means, give it a spin, it's free and actually a jolly good romp before tackling the complete game.

*Worth mentioning is what appears to be an impossible-to-win scenario, Lay A Trap.
- the AI that keeps spawning units, including three Swamp Dragons (at one point, I was battling six of them, in addition to the ground troops);
- said ground troops - various types of lizards, no problemo here - didn't seem to have any penalties/disadvantages when fighting out of the water, despite unit specs/story dialogue pointing to the contrary;
- no matter when, how or where you approach the enemy, it will trigger non-stop assault waves;
- it was the only scenario in which I got Diseased units (at one point, four in the same turn), with no apparent spotter/caster present.