This game has received criticism and praise from members of the Steam community and elsewhere, so I thought I'd put my two bits in.
Characters - Very Good
Despite a massive cast of around 35 party characters and at least 40 more supporting characters, they managed to make each character distinct, someting I, as an amateur writer, found quite impressive. Murmina ftw. 5/5
Generations - Mostly Good
One of the most interesting parts of this game was the different sections of the world that you explored over time, and each place with a different descendant. Ultimately the game if divided into five different stories, each 24-30 hours long. The generations also vary greatly in quality, from really good (Gen 3) to really bad (Gen 2). For the most part it managed to keep things interesting over the ~140 hours this game takes to complete. 4/5.
Story - Somewhat Good
The game's story is mostly character-driven, with the plot itself being a somewhat cliche "Forces of Light Vs. Forces of Darkness" routine. I personally found the story enjoyable in tis own way, albeit somewhat monotonous at times. If you came here thinking Agarest is like Final Fantasy Tactics you're in for an unpleasant surprise. 3/5
Combat - Somewhat Good
For a game that has so much combat, the system seems somewhat half-baked. Most battles are on a static, flat arena with your party on one end and the enemies on the other. The game has an innovative way of attacking, requiring that you create formations so you can layer on immense combos and artes. I found the whole arte component quite well done, leaving me with no shortage of fancy combinations I could use. However, there became little point when I started to uncover artes like Abyssal Fear, which can literally wipe the entire enemy party with little effort. I would strongly reccomend looking at a guide for the combat system, since the tutorial is pretty bad and it took me forever to learn how to not lose at least one party member per fight. 3/5
Turn System - Mixed
Not much to say here. By fighting battles and the like on the world map, a turn counter increases its count. While there are some events and the like that can only be viewed before a certain turn count is reached, it has little effect overall. 3/5
Fan Service - Mostly Bad
If you've ever googled any of the Agarest games, what you'll get is a flurry of pictures of scantily clad women, not pics of the battles or story. This game just has that much service. While most of it can be avoided, there is always a suggestive scene at the end of each generation (except maybe the last). The fan service even reaches the point where it begins to subtract from the overall plot, and can be just plain tasteless. 2/5
Crafting - Bad
This is one of the game's biggest criticisms. The crafting system is very counterintuitive, requiring the player to remember what each item converts into and remember which enemy drops which items. Most of the time I need a guide just to figure out how to make the simplest weapons. If they improved their logistics and made some items easier to farm then I would have a much more enjoyable time upgrading my gear. 1.5/5
Dungeons - REALLY BAD
A part of the game I really wish they'd left out. The dungeons are lackluster and sparsely populated with aesthetics; the rooms are used and re-used from a small set of templates, sometimes with minor modifications to make them look different. You can run through any dungeon virtually unopposed, since the time until an encounter is reset in a new room, making dungeons a bland 10-15 minute hike if you put in any effort to avoid random encounters, some of which can take a full minute or longer. Some dungeons, like Gen 3's Frozen Woods, are way too confusing without a map and require a guide or a good deal of luck to navigate them with any success. 0.01/5
Overall - Mostly Good
All in all, this is a decent game considering its length. If it happens to be on a 50% off sale or better, there's really no good reason why you shouldn't try this game.
My advice, though: Have a walkthrough handy. It makes the entire experience more enjoyable.