Bombing Busters

The first level doesn't throw much at you. Just 3 tree enemies that don't do anything except running around. Even without proper power-ups, you can get 3 stars (not required for this trophy) on this pretty easily. Just bomb a way through to them and kill them.

Note: The tutorial level is not required for any of the trophies, though I still recommend playing it to get a feel for the games mechanics.