If the target square is impassable, the whole spell gets canceled. I dont think thats intuitive given how e.g. bursts work in comparison.
I agree! Not sure how quickly we'll get to this, but I hope @Jon also agrees and we can fix it relatively soon.
Well it's not a burst card (I know you weren't saying it is), and terrain attachments do "fizzle" on impassable terrain. So it's not entirely counter-intuitive. But it does seem that probably the other two tiles should still appear.