This is a freemium game review, in which we give our impressions immediately after booting a game up, again after three days, and finally after seven days. Click on the links to jump straight to day three or day seven.
Zynga's latest is a fantasy-themed action-RPG that casts you in the role of a Summoner, able to instantly call upon the services of heroes to fight monsters in simple touch- and swipe-based combat.
It benefits from Zynga's typical production polish, and its hack-and-slash battles are immediate and accessible. And with guilds to join, new heroes to summon, and new weapons and armour to unlock, it boasts plenty of hooks designed to encourage long-term engagement.
At least, that's the theory. A week with Battlestone should be enough to find out whether it's compelling or deep enough to maintain your interest.
A pleasingly brief story setup lets you get to the action quickly: you're fighting in an ongoing conflict known as the Void Wars and given a hero - in my case a grunting barbarian - to smack around goblins and other fantasy archetypes.
You couldn't really ask for simpler controls - you tap where you want your warrior to move, and swipe enemies to attack them.
I draw an arc across three impish enemies and my hero moves swiftly between them, swinging his club and defeating them all without suffering so much as a scratch in reply.
I'm given coins and a silver star for winning the battle, which it turns out is one of several modes on each battle map. Minion Hunt is self-explanatory, while Spire Smash asks you to destroy purple spikes poking through the ground.
Treasure Raids hide three keys which open a chest containing a cash reward and a piece of armour, while Duels give you the chance to battle another player's warrior for increased Renown and the Battlestones you need to summon fresh fighters.
Instead, I opt to spend some gems on a more powerful character, an uncommon mage with two powerful ice spells. I think I'll stick with her for the time being - she can launch bolts from distance, and zip away from danger with a double-tap.
So far, the action's smooth and the art is colourful if a little generic. I have concerns about repetition, but hopefully that will change when I unlock some more heroes to play with.
Well, I'm trying to unlock new heroes, but it's not quite working out as I hoped. There are three types of hero you can summon - your battlestones can be exchanged for a 'standard' hero, while it's 140 gems for a 'super' one, and 320 for an 'ultimate' warrior.
Amusingly, the size and position of the summoning plinths you feed your currency into lets you know exactly which one Zynga would prefer you use. The ultimate heroes emerge from a tall golden one in the centre, while the battlestones are fed into the stumpy little one tucked away on the right-hand side.
I've already spent money on a bag of gems so that I could afford an uncommon hero. My next set of battlestones earns me a Hale Trapper who wields an ice bow, but he's similar in practice to my mage, only without the ability to instantly leap out of harm's way.
Thankfully, you can fuse heroes to make existing ones stronger, so the Trapper is soon used to level-up my mage.
Trouble is, I'm finding her awkward to use in the harder levels. Now that I've beaten a few maps, I need to complete some game types three times - across three different difficulty settings - before the boss battles will unlock.
On Easy and Medium I'm presented with few problems, but on Hard the slight delay between tapping to cast a spell and the bolt being hurled makes combat against larger groups more difficult.
When you're trying to fend off a number of enemies, the game can read two spells as a double-tap, which makes my mage teleport herself into the fray. Her melee attacks aren't good enough to compensate and enemies are hitting much harder.
You can use six gems to instantly restore your HP, but I'm rapidly running out. Clearly, I need another hero I can swap to in a pinch, but my recently unlocked grass mage doesn't cut it at Level 2.
One IAP later and I've got enough to afford another 'super' hero. And it's… yet another mage, albeit this time his spells are blessed with the fire element. Hardly the answer to my prayers, but at least he should allow me to last a little longer. Fingers crossed…
Five maps in and I'm beginning to flag. Battlestone's relentless scraps and increasingly steep difficulty curve have taken their toll.
I created my own guild the other day as an attempt to break the repetition, though it's only attracted a handful of interested parties (indeed, membership at the time of writing has dwindled to two) - and so I've no chance of breaking into the top three guilds who get the weekly gem prizes for finishing top of the tournament leaderboard.
It seems you need a certain amount of Renown to join the top guild - though there appears to be no way of telling what the amount is - but with a maximum of 50 members and no one looking like making way any time soon, it doesn't seem I can jump ship and ally myself with the top dogs.
In the meantime, I've been watching my Renown level fluctuate as other players engage my Mage in battle - outside my control, she's only won two of six skirmishes.
I've unlocked a new game type at least - Chest Defend sees you running between a number of treasure receptacles and protecting them from waves of baddies. Keep them intact and you get to keep the contents, which so far have been singularly disappointing.
The same goes for Battlestone as a whole. It's a bit of a slog, really, and the only way to avoid that is to pay. I ended up fusing my Ice Mage and Fire Mage to make the latter more powerful, but he only gained two levels in the process - not enough to make the Hard objectives noticeably easier.
His Inferno special move is arguably more useful, creating a wide circle of flame that engulfs any enemy in the vicinity, but otherwise I'm still reduced to lobbing projectiles from a distance, then dashing out of trouble.
It's a real pity, because with a bit more variety, and a little more development of guild functionality and the duel mechanic - and if gems were a little easier to come by - Battlestone could be something much more than it is now.
But as things stand, it's tuned more towards lightening your wallet than keeping you entertained. Only the very patient need apply.How are you getting on with the game? You can tell us and the rest of the PG community about your experiences by leaving a comment in the box below.