Follow the instructions below to find all of the Soul Gems.
Hoot Loop - Go to the center of the hub world and climb up the Mushroom Staircase. Stop when you reach the large branch partway up and pick up this soul gem.
Smolderdash - Once you can access the Under-Hollow (after you complete Motleyville), open the elemental doors inside to reach this soul gem.
Pop Thorn - When you reach your first set of blocks in Old Treetop Terrace, push the first out of the way so you can reach the next group, and push the block on the left forward. Climb up to reach this soul gem.
Magna Charge - There is a series of ledges to the left of the area where you fight your first Chompy Pod. Head down the ledges to reach Honey Trove. The soul gem is on the other side of the bridge.
Countdown - When you reach the first wooden gate in Luau Lagoon, there is a ledge to your left. Climb up the ledge to reach a broken walkway with this soul gem at its end.
Slobber Tooth - You will reach a branching path after Gobblepod Sanctuary. Take the left path and destroy the wagons to reach a hidden area. In the hidden area, turn right and use the rock to reach the lower level. Make your way across the rocks to go outside and reach this soul gem.
Rattle Shake - When you reach the rock puzzle, go to the two rocks sitting side by side. Push both of them forward. Go to the row of rocks behind them and approach the second rock in. Push it forward twice and then back once. Go to the vertical line of rocks and push the rock second from the back to the left. This will open your path to an area from which you can drop down to reach this soul gem.
Zoo Lou - Make your way to the top of the hill in Broken Bog Bay, and approach the two sheds that sit side by side. Push the one on the left forward and push the other one to the left. Next, go to the shed furthest in the back and push it to the right twice. This will open the path to reach this soul gem.
Free Ranger - In Muddy Marsh Village, go into the Jug Jamboree Inn and head up the stairs. Get rid of the debris to unblock a door through which you will reach a walkway with this soul gem on it.
Bumble Blast - When you reach the walkway after the fight with the Evilized Boghog, turn right and follow the path to this soul gem.
Roller Brawl - Head through the gate in Western Watch and turn left. You will reach a bounce pad that leads to this soul gem.
Star Strike - On the far side of the spiked walkway in Monkey Monk's Path, turn around to cross a series of stones that lead to this soul gem.
Iron Jaw Gulch
Wind-Up - Turn right after you cross the first bridge, and jump down to a ledge. Go around the cactus and make your way across the rooftops to reach this soul gem.
Grim Creeper - When you reach Sun Smoked Strand, jump off the ledge to the left of the nearby Swap Zone and make your way to the bounce pads. They will take you to a rooftop, where you will find this soul gem.
Grilla Dilla - Defeat the Chompy Pod in Okey-Dokey Corral and use the uncovered bounce pad to reach a rooftop. Break down the wooden water tower on the roof to reach this soul gem.
Boom Jet - Before pursuing Baron Von Shellshock across the mine rails, climb up the ledge and crates to the north to make your way to this soul gem.
Night Shift - Pass the crane hooks in Soggy Fields and cross the series of tires. On the other side, jump down into the mesa and search the area to find the soul gem.
Scorp - Keep an eye out for a ledge to your right as you make your way through the Stack O' Trains. Climb up the ledge and follow the path to find this soul gem.
Rip Tide - When you reach the pools along Guardian Gangway, enter the one to the east to reach a secret area that contains this soul gem.
Wash Buckler - Before you reach the first mines on Hazardous Highway, turn left to find this soul gem along a short path.
Fire Kraken - Break the crates by the exit to the Underground Lake. Use the uncovered bounce pad to make your way to a series of rotating platforms, which you can cross to find this soul gem.
Spy Rise - In Gift Boat Row, turn left and cross the spinning platforms to find this soul gem.
Dune Bug - In Paleo Pass, the geyser will send you to a series of platforms with rocks on them. Push the rock closest to you over the edge. Jump down after it and push it again so that you can climb up to a ledge that contains this soul gem.
Stink Bomb - When you reach the rails in The Frozen Curtain, cross the platforms to your left. You will reach a small break in the fence. Drop down to find a hidden wheel. Turn it, and you will activate more platforms that lead to this soul gem.
Rubble Rouser - After you free the final two snowmen in Diamond Docks, go to the ledge that contained the eastern snowman. There is a series of platforms you can cross to reach this soul gem.
Fryno - At the Typhoon Trail, you can jump down the right side of the cliff to reach a cave. Pass through the cave to emerge near the start of the level. If you follow the trail, you will reach this soul gem.
Trap Shadow - When you reach the Battle Gate in Ice Break Atolls, head through a narrow gap between two trees. This path will lead you to a hidden area of Perilous Precipice. Make your way through the exploding snowmen robots to find this soul gem.
Blast Zone - Once you get access to water balloons, take one back to the burning gate near the start of the level. Extinguish the flames on the gate, head on through, and cross the platforms to reach this soul gem.
Freeze Blade - In Birchberg, head left when you pass the first burning gate. You will reach a series of platforms you can cross to reach this soul gem.
Scratch - When you see the flame jet in Forest Path, turn left. Jump across the flame jets to reach this soul gem.
Punk Shock - Once you get your sheep disguise, you can use it to make your way up the stairs to your left, where you will find this soul gem.
Doom Stone - In Glob Lobber Gangway, turn left and climb the staircase to reach a long series of platforms. Make your way across them to reach the final soul gem.