In 3D Dragon Duel, you (as a dragon) must clear out several castles from other enemy dragons and dinosaurs, while avoiding deadly lava pits and floating spiked balls.
Gameplay is a mixture of platforming and 3D action, similar to Joust, only without giant ostriches. You have to bump enemy dragons from above to defeat them (attacking them from the sides or below will only kill you). Once they're beaten, they release a coin which will grant you bonus points. The floors are also plagued with dinosaurs, which you can destroy with your dragon's fire breath. Once you've done in all the enemies, you advance to the next level.
Some levels also have closed paths which can only be opened by finding keys laying around nearby.