The appeal of tablets, particularly Apple's iPad, as gaming devices cannot be denied Nintendo CEO Satoru Iwata himself has admitted that these devices have changed the gaming industry considerably, despite being initially dismissive in the past. This is a strong indication of tablet influence on the current market since Nintendo is the maker of the most successful handheld gaming device at the time - the Nintendo DS - and would have gained nothing from admitting territorial encroachment.
However, for the most part the iPad and its sister devices are still dismissed as a platform infested by casual games, which are fun and enjoyable in short bursts but do not take advantage of the available number-crunching and polygon-pushing power at the devices' disposal. This has some basis in fact, considering that many of the most popular games on the iOS platform are also available as browser-based games on the PC. In a way, many gamers are disappointed that something with half the power of a current gen console is nothing but shovelware heaven.
The iPad's Capabilities as a Gaming Device
The original iPad has already been discontinued, so there's no sense in discussing its specs. But the oldest available model, the iPad 2, has under its hood a dual-core ARM Cortex A9 CPU clocked at 1 GHz, 512 Mb of DDR2 RAM (clocked at 1066 mhz), and a Dual-core PowerVR SGX543MP2, which is the same graphics chip on the PS Vita, albeit with a reduced number of cores (2 compared to the Vita's 4.)
What all the numbers point to is that the iPad 2 (and its more powerful newer iterations) is powerful enough to run the Unreal 3 Engine, which is used by a lot of current gen console games. Outside the lack of physical controls, there's nothing preventing the iPad from having console-quality games.
Console-Quality iPad Games
The truth is that developers themselves have recognized the polygon-pushing capabilities of the iPad, and have tried porting some of their AAA titles on it, to varying degrees of success (that mostly border on poor to awful). The main hurdles that they have encountered usually amount to the lack of physical buttons and controls, as the ports were either bogged down by unresponsive touchscreen controllers or watered-down gameplay as they try to simplify the mechanics in order to make it playable using swipes and QTEs.
The good news is that there are developers out there who address the differences between the iPad 2 and conventional gaming devices, which allowed them to create video games that are at least on par with current gen titles, without being hampered by lack off or poor controls. There are numerous games that fall into this category, but the 5 examples below are noteworthy because they are FREE.
1. Dead Trigger
Madfinger Games' Dead Trigger is a mission-oriented First-Person Shooter that puts you in the shoes of a zombie apocalypse survivor. The game has your character try to win the favor of an established group of survivors by completing various missions such as supply runs, defense (which is basically a timed survival run) and of course, the normal "shoot any undead the moves" mission.
Dead Trigger is easily one of the games that you can bust out if you want to show off the iPad's capabilities. It runs silky-smooth and has superb lighting effects. It actually looks better than the Left 4 Dead 2 in some aspects, minus a bump map here and there. The controls may take some getting used to, but it's a fairly easy transition from the mouse + keyboard combo and is more accurate than a gamepad once you get the hang of things.
2. Injustice: Gods Among Us
Injustice: Gods Among Us has several of DC Comics' superheroes and supervillains (or at least, alternate reality versions of the characters) fighting against each other in 3 on 3 bouts, where they punch, kick, blast and even hit each other with cars. The story deals with an alternate future in which a Superman who's just lost Lois Lane to one of Jokers' schemes, has decided that he will stop pussyfooting around evil - so he enlisted other heroes (including Wonder Woman) in an effort to create a metahuman regime and put the entire world under his rule. Several other heroes, led by Batman, have gone underground as Insurgents aiming to put a stop to Superman's regime. The villains are also split, with some throwing their bets on the Caped Crusader and some joining the Kryptonian as enforcers.
While Injustice: Gods Among Us looks like a direct port of the console versions, it's actually an entirely different game as it relies on a simplistic touch and swipe control scheme where you tap, swipe, and push on-screen buttons to launch melee and special attacks (including cinematic super attacks).
Injustice: Gods Among Us is the perfect example of a developer knowing that a game that requires precision button presses (such as most fighting games) would not be enjoyable on a virtual touchscreen, so instead of squeezing a 1:1 translation out of the iPad, they simplified the controls to adapt to the platforms' strengths and weaknesses, while fleshing out the game in some other parts. In this case, it is done by including a leveling and card-collecting function into the game.
The gameplay is not deep enough on its own to elevate Injustice: Gods Among Us as a fighting game, but the card collecting and leveling parts will keep you playing for weeks, just to collect your favorite heroes, and get them to a level where they can use their ultimate attacks.
3. Asphalt 7: Heat
Asphalt 7: Heat is one of the free racing games on the iPad that actually takes full advantage of what the device has to offer. While most racing games on the iPad are content with just offering tilt controls, Asphalt 7 also offers virtual buttons, simplified touch controls, and a virtual steering wheel.
As for Graphics, it is beautiful when it comes to both the cars and the tracks, but the iPad 2 seems to be struggling a bit as you're bound to encounter some lag during extremely crowded situations. The experience will probably be a bit smoother on more powerful iterations of the tablet. Still, it remains playable even with the occasional stutters.
The main meat of the game is with the car upgrades. The money you win from races can be used to buy other cars or upgrade your existing one with parts that increase performance and handling, or at least ones that improve the look. There's an in-game store, but like most of the titles on this list, there's no need to spend money unless you want to get every upgrade as fast as you can.
Six-Guns is a third person shooter set in the wild west, and puts you in the role of a Cowboy who goes around righting wrongs and shooting a bullet or two into outlaws who were unlucky (or stupid) enough to get in your way.
Like Dead Trigger, Six-Guns uses a mission-based system to get you to places where you can shoot down bad guys and earn rewards, which you can use to upgrade or buy new guns, as well as purchase other cosmetic stuff.
The graphics in Six-Guns are well-done, and look decent enough to be mistaken for an early Xbox 360 game. However, it kind of struggles a bit on an iPad 2, resulting in frameskips and stutters during busy firefights. It's not gamebreaking in any sense of the word, but don't expect smooth-as-butter gameplay. As mentioned above, you may see better performance on the newer iterations of the iPad.
5. Dungeon Hunter 4
The fourth installment in Gameloft's Dungeon Hunter series is the closest you'll get to a Diablo experience on your iPad right now, as it lets you play one of several different classes of fighters (and get to choose your own gender as well) as you go on a quest to rid the realm of a powerful, malevolent entity, laying some medieval-fantasy flavored smackdown on any demon and bandit that crosses your path.
Dungeon Hunter 4 marks a drastic change in the series, as you're no longer constrained to a single arena during missions. Instead, you traverse an expansive world and talk to NPCs who will then give you missions. During your treks from one town or NPC to the next, you can fight various monsters or rogue NPCs, ensuring that there are no boring idle parts on the game. The upgrade and equipment aspect of the game remains the same, where you pick them up after being dropped by slain opponents or you can buy them from shops. The equipment can be upgraded as well and slotted with gems in order to improve stats, but unlike Diablo 3, the gear will not degrade over time. So there's no need for repairs or conservative use.
Graphics-wise, the game doesn't really show off the iPad's capabilities, as third person dungeon crawlers don't really require that much graphics fidelity. However, it looks good enough to be considered one of the most gorgeous examples of the genre, with lighting and foliage effects that make you want to take a rest from all the fighting and just explore the land.
Control-wise, Dungeon Hunter is one of the few games on the app store that makes effective use of a virtual joystick and button, probably because the type of game doesn't require precise controls added to the sensitivity of the iPad's capacitive touchscreen. I could see this type of game having problems with a resistive screen unless you use stylus-type point and click controls.
Note that games on the app store, particularly ones offered by Gameloft, tend to change prices from time to time. Which means the above games may lose free status any time, but they're mostly in rotation so they will go free again or get removed from the app store entirely (Apple has a tendency to remove games that are not regularly updated). In any case, you can look for games that are similar based on the recommendation. Additionally, games that you have already downloaded on your iPad during its free phase can be redownloaded again on the same device even if the developer has already changed it to a paid app.