Here is the full list of all 30 Undertale trophies - there are 14 bronze, 10 silver, 5 gold and 1 platinum.
Reach Hotland 3F.
Reach Hotland 2F.
Enter Hotland.
Reach the place where it rains.
Arrive at Waterfall.
Get to the Spaghetti save point in Snowdin.
Get four items.
Get three items.
Arrive at Snowdin.
Get two items.
Get an item.
Reach the mouse hole in the Ruins.
Enter the Ruins.
Obtain all other Undertale trophies.
Reach the second save point in the CORE.
Donate 2G to the Dog Shrine.
Donate 6G to the Dog Shrine.
Donate 12G to the Dog Shrine.
Donate 20G to the Dog Shrine.
Donate 30G to the Dog Shrine.
Donate 43G to the Dog Shrine.
Donate 59G to the Dog Shrine.
Donate 78G to the Dog Shrine.
Donate 100G to the Dog Shrine.
Donate 125G to the Dog Shrine.
Donate 155G to the Dog Shrine.
Donate 190G to the Dog Shrine.
Donate 230G to the Dog Shrine.
Donate 280G to the Dog Shrine.
Donate 350G to the Dog Shrine.