Been playing Neverwinter a bit too much that it got me thinking about a game idea.

A pirate band calling themselves the Cursed Edge is laying siege to the city preventing any shipping from docking or leaving.

Part of their schtick is that due to a curse their members are doomed to rise as undead when they die even knowing this and acting accordingly even burning or decapitating their bodies doesn't keep them down!

The game starts with the PCs waking up on the shore having managed to swim to shore after their ship was sunk.

Even the trip to the nearest safe haven is filled with danger as the safest course means using the city's sewer system to get inside before you're spotted by the pirates or their allies.

Even then it becomes clear the attacks are largely diversionary in nature and you end up being the only ones able to stop the city falling to the pirates from an attack at the very heart of the beseiged city...

Too much detail or not interesting enough?

depends on what kind of an adventure you want, I guess. If you're going for a combat oriented thing, with light story - sounds fine. To my personal preferences, I'd be interested in having more story background about things, and different ways this can be approached.

I was picturing the city was being protected by an artefact, the bad guys need someone to steal it and bring it out of the city causing the city defences to fail.

Although the theft is successful the PCs interference causes a member of the city guard arranging for the PCs to go recover it to prove their innocence.

The real question is how to run this so they actually willing to play along or actually want to help since it's rare in my experience for players to stick around the same city until they're ready to explore?