Collector is awarded for finding all eighteen trophies across single player and co-op.
You will need an extra controller, for this one, as there is no online; however, you can easily control both characters, so you do not necessarily need a second player.
Be warned that two of the trophies are found in the Sunshine Headquarters. If you beat the game, you can not return to collect them later. You will also lose all of your trophies whenever you start a new game, so it is essential that you get the two trophies in the Sunshine Headquarters.
0 - Walking Piku (1:08)
In the village, jump on the umbrella on the roof of the painter's house to jump into the clouds. You will find the "Walking Piku" trophy directly to your right.
1 - The hidden rock (1:20)
In the village, head to the far right, and drop down into the chasm. Head left, and kick down the breakable rock to reveal a cave entrance. Enter the cave, and head right to break the hidden rocks tea set. They will challenge you to a game of hide and seek.
Kick the hidden rock, hiding in the following locations:
1 - sitting on the Mr Sunshine sign, directly to your left when you get back to the surface.
2 - on the roof of the windmill at the start of the village.
3 - on the cloud directly below and to the right of the cloud where you collected the Walking Piku trophy
Return to the hidden rocks cave, and you will find the "The hidden rock" trophy just outside. Note that you might have to wait a few minutes - for me, it did not appear straight away.
2 - Baskick champion (2:06)
In the village, enter the house with the picture of the watermelon being kicked out the front. Talk to the Baskick champion, and challenge them to a game of baskick.
Beat them at a game of Baskick. You shouldn't find it too difficult; try to position yourself to the right side, under the score board, to kick the ball directly into the basket. You can also get repeated goals when the ball is pushed back towards the centre of the screen.
Once you beat the Baskick champion, exit their house and jump onto their roof for the "Baskick champion" trophy.
3 - Sam the slime (2:28)
Towards the end of the valley, just before you enter the forest, enter "Sam's Potteries". Kick or push the pots off of their shelves, and exit the house to find the "Sam the slime" trophy.
4 - The resistance (2:45)
In El Bunko, head to the room on the top right hand side. You will find a hidden section in the wall to your right, where you will find the "The resistance" trophy.
5 - A giant robot (3:01)
In the forest town, head directly left from the entrance to El Bunko, and you should fall into a hidden section of the mountain. Head around to the squirrels acorn stash, and you should find a hidden section in the wall directly to your left with the "A giant robot" trophy.
6 - The demonic toast (3:20)
In the forest town, head left from the village and enter the house with the community board. Once inside, kick the toaster to summon the demonic toast. Talk to the demonic toast, and ask them to transport you to Toastopia. Complete toastopia, and back to the shop. Take the zipline to the right of the shop up to the musician's house, where you will find the "The demonic toast" trophy.
7 - PikDug (3:45)
After completing PikDug to find the key to the mines, you will find the "PikDug" trophy on the roof of the cabin to the mines. Through playing the main story, this trophy can not be missed.
8 - Piku at the beach (4:00)
After defeating the giant robot of the forest and receiving the water hat, return to the mountain at the start of the game. Head left and jump up past the entrance to Piku's cave until you come to a platform flower. Water it, and jump up the flower to your left to enter the beach.
Head down the left side of the mountain until you hit the sand. Head back up the mountain to your right, and you should automatically fall into a hidden section of the mountain with the "Piku at the beach" trophy.
9 - The worms (4:43)
After you meet the mother worm, in the lower mines, and travel through the pipe leading into the next section of the mines; head directly left, and kick down the breakable wall to reveal a hidden section with the "The worms" trophy.
10 - Ernie the worm (4:50)
After you rescue Ernie and return him to the mother worm, you will find the "Ernie the worm" trophy right next to the entrance to the mines. Through playing the main story, this trophy can not be missed.
11 - Sunshine Inc. robot (5:09)
This trophy is found after the "Mr. Sunshine" trophy, and can be missed.
When you are in the room with all the lasers, you will have to traverse a series of ducts to open up the door. Before you exit the duct through the vent to the small room with the console to open the door, interact with the console on the left to close a section in the previous duct.
Return back to and enter the first vent in the room, and ride the fan directly to your right. The section you closed will block you from reaching the top, allowing you to head left and exit through another vent, where you will find the "Sunshine Inc. robot" trophy.
12 - Mr. Sunshine (5:39)
This trophy is found before the "Sunshine Inc. robot" trophy, and can be missed.
When you are in the room with the multiple office levels, you will eventually turn on a second fan inside the duct, and ride it all the way to the top. Before you head right to exit the room, head left into a hidden section to find the "Mr. Sunshine" trophy.
13 - Piku & Niku I (6:13)
In the first co-op level, when you reach the first set of anchor swings, use the anchor swings to swing up and onto the platform directly above. Stand at the right corner, and boost jump by standing one character on top of the other, having the bottom character jump, and having the top character jump off of the bottom character at the height of their jump. You will have enough height to jump into the hidden section to your right, where you will find the "Piku & Niku I" trophy.
14 - Piku & Niku II (6:37)
After you pass through the door that requires the three blue balls on the red switches, you will come to a zipline. Use the zipline to head up and to the left, and use the anchor swing to swing up and onto the platform directly above you for the "Piku & Niku II" trophy.
15 - Piku & Niku III (6:56)
After you pass the first door, you will come to a drop with two paths. Take the right path, and at the bottom, head right. Jump across the platforms to reach the ledge with the "Piku & Niku III" trophy.
16 - Piku & Niku IV (7:25)
After you swing across the series of swing anchors, you will come to a chasm with a basketball hoop. Drop into the chasm and head left. You will find a hidden section in the wall to your left with the "Piku & Niku IV" trophy.
17 - Piku & Niku V (7:50)
After you zipline across the purple pool, you will come to two trees. You will need to boost jump one of the characters up onto the ledge with the second tree. Jump into the second tree, and jump up and onto the small diamond platform directly above you. Jump across to the small diamond platform to your left, and use the anchor swings to swing across to the left. You should be able to swing across into a hidden section in the wall, where you will find the "Piku & Niku V" trophy.