Ok, anyone who has read some of my rants about microtransactions will wonder why I decided to play this f2p smartphone game... until you remember I'm also a Nasuverse fanboy.
I made the questionable decision of picking this game up about two and a half months ago, and since then I've been left with a lot to ponder. First, I'll list what I like about this game.
1. Relatively easy to play for free, in the sense that simply doing free quests and story quests can get you the in-game Saint Crystals necessary to roll for higher-rarity servants with only a bit of patience.
2. Charity Servants, the ones that you can get from completing event quests, are often really good (there are exceptions, even so far, but meh), so if you just do the events, you can still build a decent party before going for the higher-difficulty story quests.
3. Leveling up Servants can be fast if you have the items ready.
4. Battle system is decent, if sometimes deliberately frustrating (to encourage you to spend money, probably).
5. Support Servants borrowed from friends can let you clear hard quests easier.
6. The story of the main game is extremely well-written (though the translators made a lot of obvious stumbles by not fixing the language into English grammar at some points).
7. Manages to recreate the often ambiguous emotions drawn out when you played FSN or watched anime like Fate/Apocrypha that gave the series such grandiosity, along with the usual Nasu humor.
1. Too many obvious ways in which they try to get you to spend money, with the constant summoning campaigns and sudden difficulty spikes during and post Camelot.
2. Blatant Japanese-style gacha-addiction builder.
3. Missions can be extremely long irl time, and AP regeneration speeds make it possible to play seven hours a day on story missions during half-AP campaigns... which eats at rl a bit too much.
My rule when playing standard video games that I already know I want is 'I'll spend $60 and no more', and I kept to that rule, with a lot of headaches from temptation and obsession with cute or awesome Servants (Evil Artoria is just sexy in her portrait at final Ascension, lol). I've managed to enjoy the story of the main game and laugh through the events so far (the GudaGuda events were hilariously designed and written). However, the lack of breathing space between events and summoning campaigns leaves me feeling exhausted even if I only play a few hours here and there. Every time I wanted to sit back and enjoy the story, there was that time limit to get all the great skill-up and ascension items I didn't want to have to farm from the game nodes, and now there is an event coming up that requires you have completed the main story through Solomon... which is annoying as hell, since BB really looks cute, so I want her in my roster to stare at with drool dripping from the corners of my mouth, like with Medusa Rider and Evil Artoria...
Yes, that is the level of obsession this game can create for Fate fans. The fact that several familiar faces are available in the beginning-of-the-game gacha (including Archer from FSN and Heracles) is tailor-made to draw a Fate fan in and trap him with his own lust. I don't recommend anyone with a collector's tendencies or addictive tendencies in general play this game, as it is a potential money sink for any such individual, sadly. Since I am such an individual, my words should have weight, lol. It takes real effort for me not to look at the summoning campaigns when I don't have Saint Crystals or summoning tickets.
On the other hand, this game manages to actually tell a good story, and, having just finished Camelot (which is a difficulty spike on par with suddenly dipping into a Souls game when you thought you were playing Ar Tonelico level), I can tell you it is worth at least going this far. While it lacks the huge emotionality of Fate/Apocrypha or the original FSN, it makes up for it with the sheer number of personal stories and glorious ends the various Servants manage to meet. The fact that this definitely feels like a Fate story in both depth and detail makes it even better for a Fate fanboy.
However, where things fall short is that we have yet another silent protagonist, similar to Fate/Extra. While this makes, justifiably, the Servants the stars of the story, it can be a bit frustrating that your only inputs are frequently humorous interjections.
Personally, one thing that has had me laughing on numerous occasions is how gloriously weird some of the Berserker characters are... since they are all psycho to one degree or the other, this can lead to some... interesting results. While our friend Lancelot from Fate/Zero makes an appearance, most of the Berserkers can and do speak, even if their manner is downright crazy or obsessive.