Thanks for the assumption, but I have played it.
Grappling hook: Just tap somewhere on the screen and you'll launch it in that direction.
Most of the magic would work the same way, excluding magic missile which would need you to hold the stylus on the screen.
I realize you can highlight things in the hotkey bar to use, and I suppose magic would work on the fly, but the grapple would be a pain in the ass.
The very best and optimal solution would be to make the triggers automatically highlight the grapple hook but that still maims functionality as you'd have to switch back to your previous hotkey immediately after. Tapping hotkeys also poses a problem in terms of quickly needing to swap weapons while still maintaining your "mouse" movements on a target. Basically there's too much for you to do with the stylus to properly manage it when things get anything more than semi-hectic.
If you want to play the "it could work" card then i'll give you that, but it'd work on such a basic level that anything outside of beginner play would be absurdly frustrating and hard to do.
