Worms

Win an online game without using a single weapon besides the Grenade. This can be boosted with a friend. Make sure you ONLY use the grenade.

Note: If you like, you can get this and 'Fast, Pink and Hard Award' in the same game. Lob one grenade and have your friend suicide either using weapons or throwing himself into the water. You can get both if you do this in a ranked match.

If you cannot get this although you only used a grenade, try doing it without blowing up mines, crates or barrels. I got this while blowing those up, but some people have had trouble unlocking this trophy.