Advertising sucked. Otherwise only problem was the same as Hercules; not enough content. Movie feels short.
Pirates of the Carribean movies feel way better by comparison. Better storytelling/structure, better jokes, funnier main character to contrast with, better villains/more screentime for villains.
Only memorable things in Sinbad are the sirens scene and the snow owl.
Otherwise both Sinbad and Hercules lack: funny 2 losers, heroes vs army fight, final boss fight, a story structure which doesn't feel so repetitive and predictable lie a video game.
I didn't like how Hercules skipped so many boss fights and locations.