Fate/Extella: The Umbral Star
is part-visual novel (like the original Fate/Stay Night) and part-Dynasty Warriors. On the one hand, you have characters monologuing and chatting with each other and on the other hand, you are in control of a badass who is mowing down hordes and hordes of enemies without breaking a single drop of sweat. But, do they mix well? No. Why? Because not only does each part get in the way of the other, but also because none of the two parts are compelling on their own.
The visual novel part is a bit too player-pandering (yes, we get it, the main character is awesome. Anything else you want to add?), a bit too verbose ("Hey guys, we gotta hurry, but before we do that, let's stop and chat for 5 minutes."), a bit too repetitive (also ties to the player-pandering) and annoying at times. Familiarity with the source material will definitely help (I'd argue it's mandatory, even if it's just the animation), but even then, there were times I was scratching my head, trying to figure out what the hell did each thing mean. There were some laughs to be found here and there, but overall, I wasn't impressed by the visual novel part, especially when it interrupted the combat.
Speaking of the combat, it plays like a typical Warriors/Musou game. You control a single character (out of a total 17) and must do battle against hundreds of quasi-mechanical, quasi-digital enemies, who come in various forms like soldiers, archers, bats, commanders and giants. In your disposal you have light and heavy attacks, which can be combined into combos, the abilities to jump, dash and block, as well as the Extella Maneuver, which acts as the game wide-area super attack/musou. You also have access to a rage mode that will grant you increased damage and defense for a short period of time. To further enhance your character, you can equip them beforehands with skills that increase their offense/defense/speed/elemental resistance, etc. and can also cast spells that can heal them, remove a status element, increase their offense, etc.
Your goal in each stage (or at least, in most of them) is to take over a sufficient amount of sectors and then defeat the stage's boss. To take over a sector, you must eliminate all the sector's agressors (commanders or more powerful monsters). Initially, not all of the agressors are present and you must lure them out by defeating enough mooks. While you're busy taking over sectors, the enemy will also be doing the same and you must prioritize which sector to help, as not all of them will offer the same points that are necessary for the completion of a stage. Allowing the strongest sectors to fall into the enemy's hands will lead to a defeat, similarly to your character running out of HP.
The problem with the combat mode of the game is that it gets pretty repetitive. While similar criticism could be levelled against games like Dynasty Warriors or Samurai Warriors, at least those games have a load of characters and stages and they also feature multiplayer. No such luck here, as the game is pretty content-lite on that department, with few characters and stages. Add to that the fact that you will almost never get the chance to use the other characters in the main story and they will be pretty much confined in the side stories and the free battle mode. While the side stories could in theory add some variety to the game, in practice, they end up feeling like nothing more than rehashes of the main story mode.
In the end, Fate/Extella's idea of putting you in the shoes of a servant fighting hundreds of mooks is not a bad idea, but it could do with more variety and more interesting and less convoluted dialog/plot. Complete list
Link to the official site: http://fateextella.com
P.S.: On the plus side, the game's Vita port is a good one, without any horrible visuals, terribly uneven framerate, or ridiculously long loading times that seem to plague your typical Vita port™.