The floor is like the first levels, but there are gaps in it. The stage looks like a wrench, and there are bananas near the gaps. The goal is located behind the second gap.
Avoid the gaps and reach the goal. As for beginners, hold straight to get to the goal.
Floor 50 and 9999 Play Points Glitch
There is a glitch that skips all the other 49 floors of Expert and warps you directly to floor 50 without actually sending you to the true Floor 50, instantly giving 9999 Play Points to the player. Interestingly, if the player uses a continue and executes this glitch, the game thinks you cleared the floors without using continues and warps you to the Expert Extra levels. However, the same glitch doesn't happen if you use a continue during Expert Extra because your game will end on Expert EX 10.
The glitch triggers if the player gets to the goal at the same frame the timer reaches zero. There should be many ways to achieve this, but the player Jcool114 managed to execute it during a speedrun with these steps. First, do nothing and wait until the timer reaches 2:00 and go forward to the goal. Then, at 0:16, hold Down+Left, and the glitch should happen. It is considered advisable to use pause buffer as the timings needs to be frame perfect. Otherwise, it may be difficult to get the proper inputs in real time.