This is my Arctic Circle simulator.
For an explanation see Mathologer's youtube video on the subject.

You can either click on the screen for each step of the simulation or simply check the "timer" checkbox.
Do note the limit for the simulation is to have tiles sizes equal to the pixels in you browser.
So it will run until it reaches this limit.

Have fun.

Run Timer

1) Mark empty 2x2 squares with yellow
2) Insert random tiles (Yellow/Red or Blue/Green)
3) Expand diamond
4) Mark opposite tiles for removal
5) Remove opposite tiles
6) Slide apart