Gnome #20 - Burt
Location: Hawkins Pool (Hawkins Suburbs)
Gnome #20 is called "Burt" and can be found behind the Women's Locker Rooms at the Hawkins Community Pool. Note that you'll first need to unlock Joyce as a playable character and use her Bolt Cutters to access this area in Stranger Things 3: The Game.
Gnome #21 - Seth
Location: Flower Shop (Hawkins Square)
Gnome #21 is known as "Seth" and can be found in the Flower Shop building in Hawkins Square. To reach Gnome #21, you'll need to first unlock Erica in order to crawl through the vent in the back after opening the door by solving a special puzzle. To solve the puzzle, the rat statue needs to face the sink, the bear statue needs to face the plants.
Gnome #22 - Rutger
Location: Hawkins Pool (Hawkins Suburbs)
Gnome #22 is called "Rutger" and can be found inside the Women's Locker Room of the Hawkins Community Pool in Stranger Things 3: The Game.
Gnome #23 - Cruise
Location: Circuit Shed Store (Hawkins Square)
Gnome #23 is called "Cruise" and can be found inside of the Circuit Shed store. Note that you can't grab this Gnome until you unlock Joyce as a playable character as you'll need her Bolt Cutters to get into the back area. Also, you can't walk in the path of the security cameras, so you'll need to time the beams and walk between them in order to reach this Gnome in Stranger Things 3: The Game.
Gnome #24 - Charles
Location: Hawkins Lab
Gnome #24 is called "Charles" and can be found early on in your exploration of Hawkins Lab. To reach it, you'll need to unlock Erica and use her to crawl through a vent. after taking the first set of stairs. You'll also need to solve a quick lever puzzle in Stranger Things 3: The Game.
Gnome #25 - Kitt
Location: Hawkins Lab
Gnome #25 is called "Kitt" and can be found outside the entrance to Hawkins Lab, by the fence up towards the left in Stranger Things 3: The Game.
Gnome #26 - Huey
Location: Hawkins Lab
Gnome #26 is known as "Huey" and is located inside Hawkins Lab and can be found after you're tasked with catching an intruder. After defeating a gang of thugs, chase the intruder through a door and immediately in front of you by a computer terminal, you'll find Gnome #26 in Stranger Things 3: The Game.
Gnome #27 - Falco
Location: Hawkins Suburbs
Gnome #27 is called "Falco" and can be found around the back of the fence behind Dustin’s house in the northwest of Hawkins Suburbs. You need to travel around the south end of the fence and up past the back of the house to reach it.
Gnome #28 - Glenn
Location: Hardware Store (Hawkins Square)
Gnome #28 is known as "Glenn" and can be found inside the Hardware Store of Hawkins Square. Note that you'll need to unlock Eria in order to shimmy through a vent hidden behind a pile of rats in Stranger Things 3: The Game.
Gnome #29 - Sonja
Location: Max's House (Hawkins Suburbs)
Gnome #29 is named "Sonja" and can be found behind Max's House in her backyard as you search for a way into Billy's Room in Stranger Things 3: The Game.