Skirting the normal weekly release cycle just a smidge, Warner Bros. and NetherRealm Studios released Injustice: Gods Among Us (Free) earlier this week, a mobile version of the upcoming console and PC fighting game of the same name that features characters from the DC Universe.

You probably remember Batman: Arkham City Lockdown ($5.99), a well-received mobile version of the full-fledged console title that released in late 2011. Injustice on iOS is along those same lines. It’s not a full fighting game, but more of an Infinity Blade-esque swipe and gesture fest. And like Arkham City Lockdown, the whole thing works surprisingly well.

The combat itself is much less complex and nuanced as something like Infinity Blade, and in fact it’s really kind of a button masher, or at least the touchscreen equivalent of one. But that doesn’t make it any less fun. Battles are 3-on-3 tag team matches where you can swap your 3 characters in and out at will. The tapping and swiping is pretty simplified, but there’s a nice rhythm to it and as you get into later battles the AI ramps up in difficulty at a nice pace. There are also some very cool looking combos and super moves for each character to pull off.

Perhaps the coolest part about Injustice is that everything is based around a massive assortment of collectible cards. You have a huge selection of character cards, covering many of the heavy hitters in the DC Universe as well as some alternate versions of them. There’s also a ton of support cards featuring characters and items appropriate for the collection of characters in the game. Finally, there are upgrade cards which let you augment your characters and their abilities.

So you have a slick little fighting system, a fairly robust collectible card system, a cool way to upgrade your characters and customize your strategies, and a visually impressive version of the DC characters and Universe using the Unreal Engine. And all this comes as a free download. Well, of course, it’s not FREE free, you know what I mean? There are plenty of opportunities to spend some cash if you want.

You occasionally earn random cards from successfully completing battles, but you can pretty much buy any of the cards either individually or in booster packs using gold coins earned through fighting. The gold currency can be purchased with real money in packs ranging from $2 to $100, and currently there’s also a $4.99 “Starter Pack" that features a Harley Quinn Insurgency card and two more random Silver level character cards. It sounds like this kind of featured bundle deal will rotate out every so often to feature different bundled content.

There also looks to be a sort of energy system where your cards will need to recharge your team after a lot of battling, either by using in-game currency to recharge instantly or waiting for them to recharge for free over time. However, it doesn’t take long to collect a good enough number of character cards that you’ll be able to swap out your team with charged characters while others are recharging, thus keeping you from hitting a hard stopping point. Also, at least in my limited time with the game, it does seem like all the collectible stuff can be earned just through dedicated play, even if it might take a crazy amount of grinding and hoping for the random bonuses to be cards you need.

At any rate, Injustice: Gods Among Us on mobile is worth checking out for free, and I’m really surprised by how much I’m enjoying it so far. It’s also got me interested in checking out the console version when it hits, and by signing up for a Warner Bros. ID you can unlock additional content in the console game using the mobile game, which is pretty neat. Players in our forums are also digging the game quite a bit, and trading various team combinations and strategies, so be sure to check out that discussion for more.