If there’s one genre that’s worn out its welcome more than any other on iOS, it has to be the endless auto-scroller in my book. Auto-scrollers may have mastered the non-cluttering interface, sure, but their one-touch controls usually sap all the depth out of the side scrolling platformers they evolved from. Now, if a game comes along that uses auto-scrolling to free its interface for actions that demand some strategic thinking and provide a layered experience, that’s something I can definitely get behind. Enter Dragon Evolution (Out May 24, $1.99), which is just the game I’ve been waiting for! It’s not perfect, but it’s an important milestone in iOS history for the way it pushes its parent genre forward.

We covered Dragon’s gameplay basics in last week’s preview. Its in-game year system suggests a level-based auto-scroller, but make no mistake — the score tallies and dragon evolution choices are breaks in a time limited but infinite scroller. The idea is to make it as far as you can during the nine years and shape the most efficient killing machine possible so your dragon o’ doom roars mightily atop the internal high score board.

And I can’t wait for that leaderboard to fill up with players’ unique end-game dragons. The game’s major highlight is the wide range of upgrade paths you can assign to your dragon over time. Evolutions not only change the dragon’s offensive strength against foot soldiers and fortifications, but also change the dragon’s behaviors when you tap at the left-hand or right-hand side of the screen. This mighty beast sets out with a bite and a head-butt but it could end up with an ice-flinging tail slap, dual-elemental fire breathing, or any number of bizarre possibilities.

With Dragon’s interface limited to left-hand and right-hand actions, only two attacks are available at any moment; the game progressively overwrites previous behaviors with new ones. That’s a limitation of the formula, but I have to hand it to the developers for effectively balancing the dragon’s elemental offenses — this is important because the game’s elements play just the role you’d expect in an RPG. As long as you assign a sensible number of evolutions to fire, ice and acid attacks you’ll almost never be left without an effective backup for dealing with the dragon’s foes.

While elemental attacks will draw most of the player’s interest at first, it’s important to pay some attention to body upgrades that improve the dragon’s stamina bar. Your own commands join enemy attacks in sapping this, but there’s not much to worry about unless you’re an avid high score seeker; when the meter runs dry all you have to do is rapidly tap the screen to build it back up, albeit at the cost of a few seconds that could have been devoted to progress. And this is the real issue I have with Dragon — the game is undeniably easy. How efficiently you dispatch enemies and avoid injury will affect your chances of making it on the leaderboard, but I would argue that a sense of immediate danger could have seriously upped the ante here. What I’d love to see in updates is a game mode that treats the stamina bar like a traditional health bar, sans the drawdown for attacks, so the repercussions of improperly handling a threat really sting in real time.

The second thing I’d like to see in updates is a pause button. For now you have to rely on the iDevice’s trusty Home button to background the app if you need to break for any reason. This is normally an incredibly risky thing to leave out given Game Center’s potential to make frame rates grind to a halt for a few seconds after resuming a backgrounded game. By some miracle that process goes off without a hitch in Dragon, making the lack of a pause button a small nuisance and not an enjoyment killer. Phew!

Yes, Dragon’s cool shadow puppets would have looked right at home in Patapon — but as long as Patapon’s creators aren’t complaining, I’m not either! Dragon has a neat atmospheric soundtrack that shifts in time with the game’s bevy of environments as the player cycles through.

iFanzine Verdict: A deep and refreshing take on the infinite auto-scroller, Dragon Evolution might just bring back some players who have long since tired of the genre. If you’re a diehard fan of leaderboard competition then it has just about everything you need at release; more casually interested players will eventually find themselves wishing for greater challenge though.