Amon Saga (1986) IMDb
The dominant local polity is a society of raiders riding on a giant turtle. A number of scummy warriors from various races gather for a test to enter the service of these raiders, who are holding a princess hostage.
Epic fantasy action, similar to D&D. If you’re itching to see the short-term legacy of Angel’s Egg (1985) tortured to a bleating pulp, Amon Saga is exactly what you want. Amano Yoshitaka wrote for both projects. There are moments of neat visual design, but the story and characters are worthless.