The locations of the ornaments in First contact goes as follows

On top of the piano










Next to the tree on the TV stand










On the Fireplace behind the photo










On the bottom shelf behind the (American)football in the closet










In the sink of the bathroom











In the tub of the bathroom

The locations of the ornaments in Domestic duty goes as follows

In the trash can in the kitchen











In the cabinet to the right of the dishwasher










Behind the bread box in the corner of the kitchen










In the Laundry room on the shelf










Next to the door to the garage










In the wheelbarrow










The last is under the back of the car

The locations of the ornaments in Close Encounters goes as follows

On the shelf behind the photo










In the bottom left drawer of the masters bedroom










Next to the toilet in the bathroom










Behind the clothes basket in the "gamer's/teen's" bedroom










On the lamp in the office room










On the middle shelf next to the Arachno-Gauntlet in the secret room

The locations of the ornaments in Major Inconvenience goes as follows

On the shelf under the scanner










In the Ice Cream freezer










On a shelf near the freezers










On top of the semi-truck










In the first wooden spool










In an open box next to the blue car










In the rain gutter to the left of the exit

The items are unlocked in a sequence, not by map. So you can go to any map and collect all ornaments and get the laser sword if its the first time.


Now I will tell you the order they come in and more about the item.

The first time you collect all of the ornaments you get the weapon "Laser Sword"
This weapon can light things on fire and is a fast melee with a fairly large range.


The second time you collect all of the ornaments you get the upgrade "Spider Noir"
This makes your screen have a noir color theme, which if you don't know is like a black and white filter but with more grays and blacks than whites.


The third time you collect all of the ornaments you get "+10 upgrade points"


The Fourth time you collect all of the ornaments you get the upgrade "Lucky Dice"
This is an item that can be equipped onto the Tracker, its a pair of red dice.


The fifth time you collect all of the ornaments you get "+10 tracker upgrade points"

The sixth time you collect all of the ornaments you get "Low Gravity"
This is an upgrade that does exactly as it says, it makes the in-game gravity lower


The seventh time you collect all of the ornaments you get the "Radioactive wasabi flavor"
This is a cheese ball flavor that turns spiders into radioactive spider


The eighth time you collect all of the ornaments you get the weapon "Laser Gun"
This is a gun that has unlimited ammo, can light things afire and has a fairly good fire rate


The last time you collect all of the ornaments you get the upgrade "Gene Splicer"
This upgrade randomizes the spider types that spawn in a level, which can create some newer experiences

The locations of the ornaments in Garden of Evil goes as follows

Beside the door behind you when you first load in










On the rail near the tree










Hanging on the closest cherry blossom tree










On the large rock next to the shrine










Behind the Arachno-Gauntlet










Hanging off the shrines corners










Hanging on the side of the exit

The locations of the ornaments in Barnstormer goes as follows

On the first food stall










On the roof overhang of the barn










On the side of the tractor










On the light over the entrance to the barn











In the hay shed across from the barn behind the support beam










Under the Assault Rifle case










On the ceiling of the barn

The locations of the ornaments in Paper Trail goes as follows

Under the couch of the first room










On the printer










Behind the drawing tablet









In the vending machine










In the urinal on the right in the men’s bathroom









In the second toilet from the left in women’s bathroom










On top of the projector in the conference room

The locations of the ornaments in Contingency Omega goes as follows

In the trophy up on the shelf in the office










In the corner behind the door in the bathroom











In the mini-fridge in the hallway










On the machine on the left side of the main room










Behind the boxes next to the door to the armory










Behind the first computer in the generator room










Behind the planter to the right in the break room

Note to get into some of the areas in Consequences you will need to complete the Arachno-Gauntlets. The locations of the ornaments in Consequences goes as follows

On the desk on the Exterminator’s office










Behind the door to the exterminator’s office










In the Partner’s room behind the file cabinet










Behind the boxes in the hallway










Hanging from the floodlight










On top of the speaker










Hanging from the letters of the Exterminator’s building