Greenfoot 3.8.1 is now out. This has our first new API method in a while. We've added a sleepFor method to Actor. This method is for use when you don't want an Actor to act at all for a little while. You might use it for stunning enemies for a while, or to have some actor only do something (e.g. spawn another actor) every N act() cycles. You can use it to sleep indefinitely if you want using sleepFor(-1); other objects can wake up an Actor by calling sleepFor(0) which replaces the previous instruction and wakes the actor up. All of this is already possible if you code it yourself using a variable to act as a counter (and it won't replace only doing parts of the act every N cycles, such as only firing a bullet every 20 cycles). But we thought it might be useful to have an easy way to do this built in to Greenfoot. It will work on Greenfoot 3.8.1 and the website, but it won't work if you use it, then load the project into an older Greenfoot.