difficulty
I really like this one. It's one of the only games you can get better at by playing.
For me the biggest trick was learning what all the diffent characters say so that i know in advance what's coming. This got my through the first four levels, but in the last level, with the dying and the dude chasing you yelling all the time, it's impossible to finish it on hearing alone.
To this point i haven't found a way to pass a soldier placed conviently close to a tree...