There are lots of lvls where fish are the extra booster (the third one that changes based on the lvl), but in a lot of them, they are useless because the lvl is concerned with popping popcorn.
There are so many times that a popcorn eating fish could have been a huge help. (I of course mean just help in the 3 stage popping process and not remove the popcorn).
Sry if this has already been suggested. Lots of ideas to go through on this page....