The ridiculous amount of fun I've had blasting through Rovio's Bad Piggies [$0.99] has really left me looking for more contraption building games on the App Store, as I really enjoyed how you not only needed to build a working contraption but also do something with it. Rigonauts was actually released on Steam before Bad Piggies hit the App Store, and judging from the trailer, is going to tickle the same parts of my brain that Bad Piggies did:
Essentially, players are put to the task of building various contraptions piloted by your goblin-like "Hobs" to fight an "assortment of strange and dangerous foes." So, in essence, Bad Piggies but centralized around an actual combat mechanic instead of just making it to a finish line or collecting as many stars as possible. Rigonauts is currently available on Steam for $9.99 , and requires Windows to play. It sounds like the iOS port is in the final stages, as they're actively beta testing right now. Either way, this is the exact kind of game I need on my iPad.