Here is the full list of all 23 Clannad trophies - there are 1 bronze, 15 silver, 6 gold and 1 platinum.
Collect all trophies.
Complete the prologue.
Complete all scenarios.
Complete Nagisa Furukawa's scenario.
Complete Fuko Ibuki's scenario.
Complete Kotomi Ichinose's scenario.
Complete Kyou Fujibayashi's scenario.
Complete Tomoyo Sakagami's scenario.
Complete Yukine Miyazawa's scenario.
Complete Misae Sagara's scenario.
Complete the Sunoharas' scenario.
Complete Kappei Hiiragi's scenario.
Complete Toshio Koumura's scenario.
Complete Ryou Fujibayashi's scenario.
Obtain a light orb.
Obtain all light orbs.
Complete the true ending.
Change class to Fuko Master.
Achieve a 64 hit combo with Tomoyo.
Achieve glorious victory in the baseball scenario!
Complete the gamebook, "Welcome to the Heartbeat ☆Academy"
Jet Saito makes his appearance.
Complete Sunohara's ending.