Overall, easy to understand and enjoy. A little furstrating at parts, and very funny at times. Just great.
Some of the puzzles and things you have to solve have very vague clues, and is thus, frustrating. Near the end, you sometimes don't even get a clue. This part was frustrating for me because they expect you to remember things you have already done. It is possible, but my memory's bad anyway.
However, when there is a clue, no matter how vague it is, the text is hightlighted in red. Important conversations are recorded for you, so that makes it easier.
Most of the humor is kind of crude. Probably one of the reasons that it's T. For example, Issun always talks to one of the female characters about her bust line. He also stares at them.