They Go Boom is a bronze trophy awarded for 30 kills with the secondary fire function of the HE .44 Magnum pistol in the single-player campaign of Resistance 2. This is easily achievable by using the magnum on the first few levels of the game. Simply fire at an enemy using L1 and then detonate the explosive glycerin round by pressing R2. This will result in a kill on lower difficulties. Repeat 30 times in order to gain the trophy.