This step-by-step will walk you through my process in creating a pocket-sized Operation game, that has my own twist.
Seeing as I intended on entering this in the Pocket-Sized Contest, I chose to use an Altoids tin for the container.
The circuit I used is the exact same as the Operation game; only I substituted the motor with a buzzer.

Most of the components for this project were already around the house, but here're some items I used:

Altoids Tin
LED
Buzzer
Laminate
Image of patient
Super magnets
Tweezers
Nuts, screws, misc hardware
2 AAA batteries

Hole punch
Soldering tools
Rotary tool or drill
Wood glue
JB Weld
Electrical tape
Sander
Straight-edge razor blade
Spray paint

I consider this more of an art project than anything, so, if you try it, you should try to add your own concepts also.

Step 1: Container

A] Sand Altoids tin
B] Spray with dark colors
C] Repeat as needed

I went with an Altoids tin to ensure I had a final project that could be considered pocket-sized. This is one of the few items I had to purchase 'cause it's not a product I much enjoy. Curiously strong? You gotta have supercalifragilisticexpi-halitosis to need a mint that strong.

To get a battle-worn look I went at the tin with a palm sander. Getting the bright colors off the tin was more-or-less what I wanted. The overall look was inspired by Bioshock. The cosmetics basically came down to what interesting little parts and pieces I had.

Lastly I toned the tin down with some darker colored spray paints.

Step 2: Find a Patient

A] Print image
B] Cut along template outline
C] Laminate
D] Cut chest cavity opening
E] Punch support holes
F] Place aluminum and cut center for perimeter

To get the Robot image I believe I searched for 'steampunk robot", or something along those lines.
I did another Google image search for "Altoid tin template" so I have a perfect line to follow when time comes to cut it.
I put everything together in Gimp Editor [like Photoshop but free] and printed. Cut before laminating

The first few bots had been laminated with packing tape. I must've done 4 or 5 and all had the long creases or folds. I finally had my wife pick up some of the laminate sheets you can find in the office supply sections of stores.

The chest needed a door as opposed to just having open wounds and since I was cutting through a much thicker laminate I used a straight edgde razor and made somewhat of a hinged door. The metallic perimeter of the chest cavity is made of a Coke can. And a new straight edge razor went through it almost as easily as paper.
I drilled a small hole in the sternum where the wire from the negative battery end will attach.

Step 3: The Circuit Install

A] Build the circuit
B] Install the circuit
C] Add supports

Again, this is the same circuit as the real Operation game; except with a buzzer instead of a motor. I even used the tweezers from an actual Operation game. The wire from the tweezers comes to an end with a 3.5mm jack, functioning as somewhat of a power switch when unplugging it. Continuing into the female component, to LED/Buzzer.

Here's a fine example: https://www.instructables.com/id/Operation-Game/

I also put some 'speakers' in the bottom of the tin so the buzzer can be heard better [just holes].
To keep the game board level and above the wires I added four bolts, one at each corner.
At this point I used the hole punch on the game board, matching the new support

Step 4: Power Up

A] Add power source
B] Solder, glue and/or fasten
C] Add game pieces and tray

I did have one solar cell, but not small enough to use and retain the aesthetics of the project. I went ahead and chose 2 AAA batteries for now, until I happen upon a solar cell that'll fit on it neatly.

I whipped up a small bead of JB Weld to hold the buzzer in place. Also, in order to make it more challenging, there is a super strong magnet on the bottom of the cap where the game pieces lay.

All of the game pieces are also conductive so that if the pieces touch the edges while touching the tweezers, it'll also cause it to alert.

Step 5: Play

I've no idea how to 'embed' the YouTube video, so here's the link for the time being.

http://youtu.be/6j5G4GjRiE4

Hope you enjoyed and perhaps got something outta this ible. If anything, at least inspiration.