mario must clean up lots of sludge and filth that is on the island. f.l.u.d.d. allows him to do this. f.l.u.d.d. can only hold a little bit of water and mario must jump into a pool of water after the water runs out to refill it. f.l.u.d.d. can also do several other things. if mario aims the nozzles down, mario can float for a few seconds until the water pressure runs out. there are also areas where mario takes f.l.u.d.d. off and jumps around himself without assistance.