My initial thoughts are to use a raspberry pi pico, GPS, and the Bluetooth LE capability of the raspberry pi pico's to make a GPS game. There will be one "main" device that has GPS, and the goal will be to collect the other devices. When the "main" device gets close enough to one of the devices that need to be retrieved, there will be some sort of indication (maybe). The goal is to have someone go to a certain number of places and retrieve the other devices/items. Maybe the items will be moving. Maybe they won't. Don't know.

So, in order to do this, I will need the following:

1. Microcontroller with BLE

2. GPS

3. All the lovely support components (cases, batteries, programming, etc.)

I've decided to use a raspberry pi pico W, since they are $6 and I wanted to try something new. I may fall back on the old Arduino Uno R3, since I have a bunch of them and can basically make them myself with the ATmega328p chips that I have. They don't have BLE, but I can get the GPS setup and perhaps just use locations instead of placing beacons. Don't know.

For the GPS, I'm using a NEO-6M. 

I'm going to use an OLED display to send information to the user.

I'm going to use a servo for any locking mechanism (if I want one). There are tutorials on how to do this with the raspberry pi pico. I already have working code for these for the Arduino Uno. 

1. Project with raspberry pi pico and GPS: https://diyprojectslab.com/neo-6m-gps-with-pi-pico/
   1. https://microcontrollerslab.com/neo-6m-gps-module-raspberry-pi-pico-micropython/
2. OLED with raspberry pi pico: https://www.hackster.io/diyprojectslab/how-to-use-an-oled-display-with-raspberry-pi-pico-d9d9cb
3. Raspberry pi pico and servo: https://www.youngwonks.com/blog/How-to-use-a-servo-motor-with-the-Raspberry-Pi-Pico
4. Raspberry pi pico ide: https://diyprojectslab.com/raspberry-pi-pico-with-thonny-ide/
5. Raspberry pi pico w BLE: https://www.hackster.io/Ramji_Patel/raspberry-pi-pico-w-and-bluetooth-low-energy-a829c7