The trophy list for Sonic Mania was recently revealed at PSNProfiles. And it looks like the game has no Platinum or Gold trophies at the moment. The game currently has 18 trophies. 3 Silver trophies and 15 bronze trophies.
We don’t know for sure if there is going to be a gold/platinum trophy since the game hasn’t released yet but at the moment Sonic Mania does not include a Gold/Platinum trophy. Some might be disappointed and others not so much.
Sonic Mania will launch on August 15th, 2017.