Battle heart is definitely great stuff. A very neat way of how you control a party of heroes fighting against enemies. You also progressively level them up and select new powers and abilities for the members. You also can hire new members throughout the game.
Others I don't believe mentioned are.
Shooter style:
Bug panic. - This is a combined game that is a level-based twin stick shooter that takes elements of scrolling shooters and top/view adventure games where you move a character across the world. This is a universal iPad/iPhone app, but with absolutely perfect controls. It's hyper acurrate on iPad and has no disconnect between you and control of the game's character. It works your dodging skills and your combo skills as your main weapon of attack is pesticide bombs.
Rogue-like:
While there are a small number of good games in this area, and with different level of complexities. Sometimes, it is the more simplistic and easiest to jump into that gets special attention. Of these, I find that Sword of Fargoal really stands out. Presentation wise, it is by far the prettiest; but more so it succeeds in one major thing. The ease for which you can jump in, play, and control the on-screen action. It isn't the most complex of the bunch. You do have games like Nethack and such. But just in controls and trying to do various actions, they lend to make things a bit complex and less iOS friendly. Fargoal gets it right by simply working real well on a touch-screen interface and trims the fat concerning what you need to do to do everything in the game. However, it is no slouch in terms of giving you a decent amount of experiences. It's level of complexity comes in things you can run into and avoids adding it in terms of player actions. Graphics mix 2d bitmap characters in 3D top/down dungeons with a neat and unique effect. Music is orchestral and pretty epic for a game type that usually is devoid of music.
Hybrid Tower Defense and Dungeon crawler:
Dungeon defenders. - The control interface could be a bit better, but this unique angle to a hybrid game is very well done. Can also be played online with others. You cam also build characters you play. Each character not only has unique loot, weapons and such, but unique towers, traps, and defense systems they can place in the dungeon to help. Those can also be improved upon as well. While it has plenty of Tower Defense gameplay, it also has dungeon crawling satisfaction in there, with various loot to obtain in the levels. Maybe not everybody's taste, but if you like Dungeon hacking lootfests And Tower defense strategy, this could be a gem for you.
MMO:
Two flavors.
1. Free to Play model where you buy specific content packages to expand your play.
Pocket Legends. - The main only pick of this lot. Not too shabby either. It's mainly the town lobby areas where you'll see other random players and such. All adventuring locations are instances, though. Almost like a 3d offline level-based adventure, but you can form a party with other online players to join you. It's third person with a mostly angled overhead camera.
2. MMO with monthly payments.
Order & Chaos online. - Also the main only pick of this lot. This is by far the most impressive online game of the online lot. At first, looking kind of like a Wow clone, it actually has a number of unique systems in place. However, the most impressive thing is that it is a fully realized complete non-instanced free roaming world MMO in your iPad or iPhone. No joke. It's right up there with the full-blown MMOs on PC and Mac and iOS is the only platform outside of them and FFXI on PS2/Xbox 360 to do so.
It's a universal App with interface differences and graphical enhancements when played on the iPad. Graphically impressive, they really learned from other full-blown MMOs and got a lot of the complex systems right, first time. And better yet, the interface is completely made for the IPad. This isn't just a WoW-like MMO shoehorned into iOS. The interface, from the ground up, was made specifically to play best on touch screen controls. Has full Guild support. Multiple chat channels that you can turn on and off, once in the game. Character creation options, and you can have up to 3 characters per account, by default.
It's handled like an MMO, with planned periodic updates, however the price of the plans is the most impressive. $0.99 for one month, $1.99 for 3 months, and $2.99 for 6 months. This technically makes it the cheapest unrestricted MMO out there.
There is one main back draw to this game. As it stands, you can only play this game over Wi-FI. While a lot of Wi-FI IPad users won't complain, since either Mi-FI or Wi-FI options work, it is a damper for those wanting to use direct 3G connections to play, including iPhone users. It's something to note since the other online games do work over 3G
Elder Scrolls/Gothic-like:
Aralon: Sword and Shadow - Is definitely my pick of this type. It's a bit more like Gothic than Elder Scrolls, but some have only played ES so I figured I mention both. This is also a free-roaming single-player RPG sandbox. It also includes mounts, in this one, from the get go. (Though Order & Chaos online should have those in an update.) Hard to say more for this one, it's a pretty good 3rd Person sandbox RPG for a portable device. Decent graphics, too, though maybe overshadowed by new games like Order & Chaos. Still, if you want a nice Single-player Gothic experience, it does a good job. Also, with the latest update for it, the iPad-specific interface was given a major overhaul. One for the better. This is a universal app, but the revamped iPad interface definitely changes my opinion in favor of the iPad being the device you'll really want to play this game on.