Yeah, home assistant is super powerful once you break out of the mold of "a light is a light, right" and realize that ANYTHING can be represented as state changes, and you can run arbitrary code based on it.

And with lights, locks, and brightness/color being able to be modeled in Hass's interface to HomeKit and Siri, you can basically do ANYTHING that can be turned into on/off, lock/unlock, or a slider.

You could probably build a remote paintball turret with it, camera for viewfinder, sliders for elevation, rotation, and azimuth, lock for arming, switch for fire.