Heroes Call recently made a big splash onto the App Store, touting itself as a viable mobile alternative for Diablo fans. Gameloft's tried-and-true Dungeon Hunters series has typically claimed that title, but is there another that can hack and slash its way into our hearts while navigating the perilous trappings of the freemium model? The control scheme of Heroes Call is natural and rich with lots of tactical depth. Attacks are automatically launched after you select an enemy, but if you tap the enemy a few times in a row, you can shoot off a combo. Double-tapping casts a poisonous damage-over-time spell, while a swipe gesture through your avatar casts a nearby area attack. You move around simply by tapping where you want to go, and you can hold down on the screen to continually move.

The usual role-playing game mechanics are here, including leveling up, unlockable abilities, and a wide range of equipment to find and purchase. Mind you, there aren't any of the traditional ability scores, like strength, dexterity, or intelligence, opting instead to mark progression with equipment. The nods to Blizzard's Diablo franchise are numerous, complete with Identify Scrolls used on ancient weapons you stumble upon, and destructible barrels inexplicably full of gold coins. Dungeons are branching, and paths that diverge from the main objective are always full of rewards.

The graphics are really sharp, and host a bunch of great lighting effects from torches and magical powers. The level environments have lots of rich textures and models. The visuals in Heroes Call are optimized for the new iPad's Retina display, if you happen to be using the third-gen iOS tablet. My only complaints are fairly minor; the running animation has a serious slow-mo moonwalk feel to it, and new equipment isn't represented on your character. The audio quality isn't quite as good. The in-game music is repetitive, and the lack of much ambient noise makes you feel like you're running around in outer space until the fireballs start flying. There is some crackling from nearby torches, but some sound effects for footsteps would go a long way. That audio that is there for monsters and attacks is fairly high quality, at least.

The biggest strike against Heroes Call is its transaction model. The game is free, so some freemium stuff is to be expected. You get a warrior class for free, but the spellcaster requires that you spend at least $2.99 on their in-app currency, gems. The developer would really do much better to just charge that $2.99 up-front and offer both classes right off the bat. At least you can earn gems through regular gameplay, but you'll have to be diligent - they don't drop often. Identification scrolls and in-game gold can also be obtained through in-app purchases.

There's one other other major problem with Heroes Call: there are timers imposed on a few of the game's mechanics, which is primarily a means to egg users to burn through gems to override the wait. Having timers on secondary game elements such as identifying magical items at the local appraiser isn't so bad, but the fact that they put this restriction onto the core gameplay for each level is absolutely ridiculous. Even after shelling out gems (which were likely bought through IAP) for a caster class, you have to wait up or pay up just to play the next level.

The story in Heroes Call is actually fairly gripping; instead of the usual spic-and-span, chisel-jawed goody-two-shoes, you take on the role of someone cast out from a typical heroic order, leaving you have to pick up the shattered pieces of your old life. Though the writing between levels is pretty good, it would be great if the game engine were leveraged to make proper cutscenes. Cloud saving is enabled through a Facebook log-in, plus the app is universal, so there's no worries about splintering your game progress or losing any gems you've acquired. Heroes Call further burrows into your social graph by offering in-game incentives to invite friends on Facebook. There's no Game Center support or multiplayer, unfortunately.

The good

Excellent graphics
Fluid controls, well-suited for hectic action
Free!

The bad

Pushy in-app purchases
Timers feel forced
No multiplayer

The bottom line

Despite excellent gameplay and sharp graphics, Heroes Call really pushes its luck on a few fronts. Players will immediately be turned off by the timers imposed on access to the core game. The required $2.99 in-app purchase to access the second class is a bit pushy, even if it has its own storyline and levels. Compared to Dungeon Hunters, I find Heroes Call feels more like a gritty dungeon crawl than an arcade hack-and-slash, which seems to me more true to the spirit of the Diablo games. If you're looking for swords and sorcery on the iPhone or iPad, Heroes Call can give you a great experience without having to spend a dime.