Run a method interactively?

[atomota]

Is there a way to run a method more interactively, as opposed to putting it into say the "when the world starts, do" method and playing the world? What I'm looking for is something like where the world is already running, and you can execute methods interactively via some sort of read-eval-print loop equivalent to experiment and get some immediate feedback about what happens, how long 2 meters are onscreen, how things work, etc.

Thanks!