Susume! Kaizoku

海戦！財宝！戦闘！
でっかい海を駆けめぐれ！

二人の若き海賊が、伝説の秘宝をもとめて旅立つ。海賊船をあやつり七つの海を思う存分暴れまわれ！子分たちに命令して、財宝、秘宝の数々を手に入れろ！大海原を舞台に、海賊たちの冒険が始まる。

Unofficial English Translation:

Naval battle! Treasure! Fights!
Run about the vast oceans!

Two young pirates set off in search of a legendary treasure. Control a pirate ship and rampage across the seven seas to your heart's content! Command your henchmen, and obtain all sorts of hidden treasures! On the great ocean's stage, the pirates' adventure begins.

Source:

Back of Jewel Case - PlayStation (JP)