Unlike the previous Lufia games, this is an action-rpg game similar to games like The Legend of Zelda, Secret of Mana, and Kingdom Hearts. Gameplay is no longer turn-based; players can roam around freely and attack monsters without waiting for the battle scene to occur. Only one character can be playable on-screen. The player can choose a map to go to without fully navigating the map like Lufia: The Ruins of Lore. Players can equip armor and weapons that can give players unique abilities in combat. The game takes advantage of the dual screen. In certain battles or puzzle-solving, certain actions may be disabled or the top-screen is used to navigate actions committed by bosses. Characters do not gain experience from defeating certain bosses. Players can press the feather button on the screen to go back to the stage selection menu. Players can also hit the rewind button to go back to the previous dungeon. These options may not be available if an essential event is going to be triggered in that area. Like in all Lufia games besides the Lufia & the Fortress of Doom, The Ancient Cave returns.
Source: Wikipedia, "Lufia: Curse of the Sinistrals", available under the CC-BY-SA License.