As you explore, you reveal parts of the story by triggering events when you've solved puzzles. Other times, just stepping on or behind an item will reveal something. The story is entertaining, some of the music is very good, and the acting is quite credible. The game does have some places where the next action may not be obvious, but the puzzles are fair enough. Exploration is necessary, and you have to take much more care in this game than a typical adventure game.
Cockroaches are much easier to kill than most characters in an adventure game.
This is definitely a save often game. The roach gets several lives, but they are quite easy to lose. Watch other roaches if they happen to be around. They may lead you to an important spot. They may also show you something to avoid, by dying in front of you.