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