and the bridge underneath Bowser collapses, causing him to fall into the lava which burns his flesh, leaving a skeleton. Though Bowser was defeated in the first world, this does not stop Bowser Jr. from running through the remaining worlds with Peach in tow, forcing Mario to chase after him before reaching Bowser's castle in World 8. There, Bowser Jr. revives his father's skeleton, creating Dry Bowser, but Mario once again defeats Bowser by dropping him into a deep pit. In the final battle, Bowser Jr. flees once more across a lava chasm to a larger castle, where he throws his father's bones into a cauldron and revives Bowser in his original form. They attack Mario in tandem, but Mario drops the pair into the pit below. In the game's final sequence, Mario rescues Peach, who kisses him on the cheek. Over the end credits, Bowser Jr. is seen dragging his unconscious father across the floor. He looks at the screen, and growls, breaking the fourth wall. Development Nintendo announced on February 21, 2006, that New Super Mario Bros. would launch for the Nintendo DS on May 7, 2006. The game's new power-ups were also introduced at the same time, including the Blue Koopa Shell and the Mega Mushroom. Nintendo further mentioned that the game would be played in 2D, but use 3D models to create a 2.5D look and feel. The May 7 release was later delayed towards May 21, 2006, but the game's release date was eventually only pushed back slightly to May 15 of that year; Nintendo also planned to release the game around the same time that the Nintendo DS Lite launched, on June 11, 2006. New Super Mario Bros. is the first original 2D platform game to feature Mario since Super Mario Land 2: 6 Golden Coins in 1992. New Super Mario Bros. was available for play at E3 in 2005. The game's designers were given much more freedom with designs in New Super Mario Bros. compared to previous 2D Mario games. Characters, enemies, and objects could now be created with much more detailed animations, without requiring that they would be designed by hand. To provide visual cues, the developers made the game's camera more dynamic; it zooms in and out of action depending on the situation to provide focus where necessary. Physics play an important role in New Super Mario Bros. improved game mechanics.