Agreed, and I'll add a few things. You can argue that lots of games can/do modify things while running. Entity systems allow components to be added at runtime.

Agreed, and I'll add a few things. You can argue that lots of games can/do modify things while running. Entity systems allow components to be added at runtime. This not only allows for different code to be executed, but also I've seen code that reads components and hot loads additional code for systems supporting those components if necessary, which can be done a number of ways, and raw from the source even. Smalltalk also supported this and isn't really functional. In addition to the Smalltalk environment itself pretty much being a live environment, I saw things like serializable continuations in Smalltalk. You could do fun things like a Gemstone Smalltalk app I saw that would take the image state and allow hot modifications via a bug tracker. There's tons of other systems for doing this. And it's also a reason why many games write big chunks of the type code you would want to hot load in scripting languages like Lua. There are tons more examples and has no relationship to functional programming other than to say that it was a common thing in the Lisp world many moons before most of these other things existed.