A Sea of Dragons is a story that branches in many places, and each playthrough may look completely different than the last. Here are a few of the challenges I recommend for those achievement-oriented players:

•  The Pacifist - Rescue your sister without hurting a single dragon
• The Dragon Slayer - Kill three dragons in a single playthrough and live to tell the tale
• The Friendly Explorer - Travel to Dragon Island with each of the seven captains
• The Family Man - Discover what happened to the father of Captain Charlotte

Feel free to talk about the challenges, or post your own challenges in this thread!

SPOILERS AHEAD:

Below is a list of all seven captains who will take you to Dragon Island:

1.  Antonio (Docks Path)
2.  Porkchop (Docks Path)
3. Kallus (Docks Path)
4. ~Indistinguishable Mumbling ~ (Market Path)
5. Charlotte (Market Path)
6. Ramla (Market Path)
7. Sabine (Hidden Path)