Here is the full list of all 11 Namco Museum Essentials trophies - there are 5 bronze, 5 silver and 1 gold.
Obtained all Dragon Spirit stamps!
Obtained all Xevious stamps!
Obtained all Xevious Resurrection stamps!
Obtained four Dragon Spirit stamps!
Obtained four Xevious stamps!
Obtained all Galaga stamps!
Obtained all Dig Dug stamps!
Obtained all Pac-Man stamps!
Obtained four Dig Dug stamps!
Obtained four Pac-Man stamps!
Obtained four Galaga stamps!