The Grenade is a toss item in the game. It is a "heavy" item, so the fan does little to no effect on it. In the levels "Boss", "Cubical(confirmed)", and "Warehouse", it has a special feature. In "Boss", the grenade and the grenade only, can blow up the fish tank, allowing easy access to the treasurer chest "goal". in "Cubical", one can blow up the chair of the man working at the desk beside the trash can. Blowing up the chair sends the man spinning in a circle on his swivel chair. this provides much comical relief for young ones (I game the game to my 4-year-old cousin and he played quietly on that one level for 2 hours). In "Warehouse", one can blow up the left row of boxes, revealing a hidden trash can that gives 15 points, as aposed to 10, when you make it in the can. Also, doing this (or burning the boxes with the flaming paper ball) unlocks an achevment called "exterminator (confirmed)". The only down side to the grenade, is the fact that if it so much as scims something, it will blow up. So, the only way to get points with it is with a "swish" (where it goes in without touching anything at all).