Hi,
One conflict in your image is that <100=BAD and =0 "What do you think about this?"
So if the value is 0 then the value is <100 as well, below is a bit altered formula:
=IF(AND($A1>=500,$A1<1000),"Normal",IF($A1>1000,"Wonderful",IF(AND($A1<>0,$A1<100),"BAD",IF(AND($A1>=100,$A1<500),"Going Hard",IF($A1=0,"What do you think about this?","")))))