I'm a big fan of the Exile/Avernum series from the same developer. For what it's worth, I think Avernum: Escape from the Pit (the newest remake of his first game) is probably the best game he made.

His games are really worth playing but you should know how they work. They are much closer to Baldurs Gate or Ultima than something like Diablo. The games are very story heavy. He is a pretty good storyteller and a really good world builder. But the game mechanics are a little poor. The skill system in all his games is generally pretty unbalanced. Some classes/skills are godly while others are less so. For example, in Avernum, archers are pretty bad, while mages and dual wielding melee are the god classes. I would look up on the spiderweb forums general character building advice before you start if you don't want to be annoyed. However, all his games do have a character editor where you can respec your party if you don't like how you leveled them, so it's not that big a deal. As well, combat seems pretty strategic early on since you are so limited, but later in the game you unlock so much powerful AOE and buffs that you can just use the same strategy for every fight of "buff up and use your most powerful aoe attacks" It's not hard just kind of boring. So just know you are getting into these games for the writing and story moreso than the interesting combat.

I haven't played them on ipad but the controls should be fine. You never have to do anything more advanced than clicking where you want your guys to go. I don't think you can even right-click or make a selection box. It actually seems like it was designed for iPad because there are some issues with the UI in the PC engines like not having a keyboard shortcut to close windows. The one thing that might be frustrating playing on iPad is the amount of items on the ground. On PC you get used to tapping the "get items" key every few seconds to see if there are any items you can pick up nearby, but this might be inconvenient on iPad.