There's a playground/sandbox mode. You can also do it in the normal BR mode. It takes a few minutes until the circle starts shrinking and it shrinks in multipl

There's a playground/sandbox mode. You can also do it in the normal BR mode. It takes a few minutes until the circle starts shrinking and it shrinks in multiple phases, so you have 5-10min (more if you're lucky) to just mess around before it gets too small.