Here is the full list of all 13 Happy Drummer trophies - there are 9 bronze, 3 silver and 1 gold.
Win "Good" rank for all music in night scene, not including self-created ones.
Win "Great" rank in any music.
Win "Perfect" rank in any music.
In daylight scene, reach 40 combos and see dinosaurs coming out to celebrate in any music.
Win "Good" rank in any music.
In night scene, reach 40 combos and see elephants coming out to celebrate in any music.
Win "Perfect" rank for all music in lunatic mode.
Win "Good" rank for all music in daylight scene, not including self-created ones.
Create your own drum music, with more than 200 drumbeats.
Play any of your own music with more than 200 drumbeats, and get "Perfect" rank.
Sign your names on local leaderboards for 30 times.
See god for 50 times. Reach 100 combos in night scene to see god.
Make volcano eruption for 50 times. Reach 100 combos in daylight scene to see volcano eruption.