It's a ripoff of a classic clicker game for phones. It's really nothing new.
I tested this on atmega 328p and 32u4 micro controllers, but it should work on others as well. The only problem might be the low power library. I used this one: https://github.com/rocketscream/Low-Power
That library works on these MCUs: ATMega88 ATMega168 ATMega168P ATMega328P ATMega32U4 ATMega644P ATMega1284P ATMega2560 ATMega256RFR2 ATSAMD21G18A
The problem with some of these might be lack of memory. Adafruit SSD1306 library uses a lot of memory, so look out for that.
I made this game a bit more interesting with added levels. You have 4 auto clicker upgrades and 4 click upgrades. To level up, you have to collect 10 of each. Levels get progressively harder and harder. I had to make my own big number notation: 1aa = 1; 1ab = 1000; 1ac = 10000000; ... 1jj = 10¹⁰⁰
When you get to that point, you've beaten the game. It will take you like 70000 years, but that's fine.
After 30seconds of not doing anything, it goes into deep sleep. You get about 1% of the revenue for 2 hours while in sleep mode. The first screen also has some power saving measures, so if you want to reprogram your MCU, you'll have to do it from the upgrade screens and not from the home screen (the MCU turns off 30 times per second, which disables all usb functionality). If you want to decrease power conumption, desolder the led that is always on. Those pesky little things add 2-3mA to the total consumption even when the MCU is sleeping, so if you want it to be battery friendly, you really have to do it.
I used pins 0 and 1 for the buttons. They work on 32u4. If you use it on other MCUs, have a look at this page to see which pins you can use: https://www.arduino.cc/reference/en/language/functions/external-interrupts/attachinterrupt/ I'm handling all the clicks with interrupts, so the pins have to support them as well. You have to connect the buttons to ground.
This game is meant for SSD1306 based 128x32 OLED displays. You can change it. I'm using the I2C kind. Library: https://github.com/adafruit/Adafruit_SSD1306
The game is being backed up to EEPROM every few minutes and everytime it goes to sleep and when you level up. IMPORTANT you have to hold both buttons during the first boot to initialize the EEPROM (you can try not doing that and see what happens).