Hey, thanks for playing and reviewing.
Impassable terrain could definately be clearer, though there is currently also an issue where sometimes certain passable tiles can't be selected for some reason, so theres a chance you might have run into one of those aswell.
Glad you enjoyed the art direction!
We totally planned on having sounds, and perhaps even a bit of voice acting but we just ran out of time. Its certainly one of the things we'd like to revisit in the future.