Throughout the level, there are several lava pits, which can instantaneously defeat Mario if he were to step in them. The landscape of the level is similar to that of regular Bowser-esque castles, containing torches, lava pits, and various spike- and fire-based traps.
The level begins with Mario atop a small ledge. After jumping down, there are some gears that he must traverse, and these gears have Podoboos jumping around them too. After going past rising lava flows and defeating a Hammer Bro., Mario makes his way to Checkpoint of the level. Afterward, a couple of Thwomps guard a narrow pass to the final part of the level. Upon reaching the last section of the level, the boss fight ensues.
Star Coin 1 - When stepping on the first gear, there is a Star Coin above a hole as it is poorly guarded by a fireball.
Star Coin 2 - Just after the checkpoint, there is a Star Coin located in the extended fire bar area.
Star Coin 3 - Just after the second checkpoint, the third and last Star Coin is guarded by the second Thwomp. It can be reached by going behind it and wall jumping to grab it.
EnemiesEnemies that appeared in World 1-Castle:
As Mario reaches the end of the level and draws near the castle, Bowser suddenly jumps down and begins to spit fireballs out at Mario. With clever jumping techniques, Mario makes his way to the bridge on which Bowser jumped onto. Here, Mario can attempt to use a Fire Flower or just dodge Bowser's jumps. Upon reaching the far end of the bridge, Mario pushes a button and releases the bridge. The pieces of the said bridge fall into the lava below, and Bowser falls in, an homage to the classic Super Mario Bros. castles. However, this Bowser is a false copy and is a Goomba that has acquired a Tanooki Suit. Mario then runs into the small castle and finds a Toad who tells him to proceed onward, to World 2.