In the past, shoot at the swing in the swing set in the back yard of the yellow house and pick up the swing seat.
Head to the present and find the RC-XD Controller around the map in one of three places.
Pilot the RC-XD into the garage and blow up the red canister in the corner.
Head down the street past where the truck was and enter the newly opened garage.
After watching the zombie disappear, pick up the Chalk that was left behind.
Head to the playground again, now in the present, and place the swing and the chalk on the swing set.
These next three steps can be done in any order and all at the same time. The goal of each is to play a game with the twins, which will spawn a gold item. You'll need to kill zombies with the wonder weapon near the gold item to take each of them to their final destination.
Music Sheet:
In the present, head to the backyard of the green house. Eventually, a zombie named the Piano Teacher will spawn.
Use an item to cause the Piano Teacher to become friendly and it'll start heading towards the piano in the house.
As it is heading there, teleport to the past and head back to the Piano.
The Piano Teacher will go to the piano and explode.
Head back to the present and there will now be eight note symbols around the map, each one blinking between one to eight times.
Note where each of the locations are and interact with them in order from one to eight.
Head back to the past and go to the piano. There will now be symbols above it.
Interact with the piano and play 86756535.
Head back to the present and find three floating zombies outside the map behind the green and/or yellow houses. Shoot all three.
Head to the X on the ground down the road and stand on it until it glows.
Head back to the past and stand in the newly formed O.
Interact with the ball and start the trial, requiring you to kill the zombies before they land back on the ground.
Once done, the golden music sheet will appear.
Music Box
In the present, head to the garage of the yellow house and interact with the red box on the shelf to acquire the Irradiated Seeds.
Head back to the past and place the seeds in the empty mound in front of a house.
Kill zombies near the tree using the wonder weapon until the tree is grown enough.
Head back to the present and head to the tree.
Throw three combat axes at the tree to acquire it's logs.
Head to the past and place the logs into the Fireplace of the yellow house and light it on fire.
Head to the present and stand on the X until it glows, then head back to the past.
After the twins use the chalk to make the Hopscotch, jump on each number up to twelve then back down to one without jumping on the black mist.
Doing so successfully will spawn the golden music box.
Cymbals
In the present, use the perk Death Perception to find an invisible headset in the map and pick them up, either on the coat rack on the second floor of the green house, in front of the green house near the car, or in the mannequin's hand next to the Random Perk Machine.
Next, there will be a set of Goggles on top of a Speaker Pole at the end of the street.
Shoot the goggles that are on top of the speaker pole to knock them down, then use a wisp from the Wisp Tea perk to grab the goggles and bring them into the map.
Head back to the past and interact with the Toybox on the side walk and place the headphones and goggles inside.
Head to the present and stand on top of the X until it glows.
Hidden around the map is a red ball, either on top of the back porch of the yellow house, on top of one of the non-yellow or green houses, or on top of a crate on the street.
Shoot the ball and keep shooting it until it's on top of the X.
Head to the past and to the backyard of the green house and interact with the Four Square game.
Keep the ball from bouncing in the same square twice or outside the squares until the game is over, spawning the golden cymbals.
After all three main steps are done, head to the present and set the timer on the tower to be at 0:00.
Head back to the past and, while in the animation, shoot at the red hand with the wonder weapon, which spawns an orb between the bus and the truck in the middle of the road.
Follow it to the backyard swing set and interact with the portal to start the boss fight.
