Rive isn't a game engine, afaik it's largely used for simple interactions and UI.
You can make a game out of simple interactions though, can't you? The developers of Rive describe it as an animation and design tool that allows interactions, but the goal is to be the successor to Flash. They are nearly there. Once they add bind keyboard inputs, if they haven't already, it's a game engine for anyone who wants to make games with it. I'm told there is already a way to work around that and add keyboard controls to your game using javascript.
I suppose the idea is to make e.g. all the UI in Rive and utilize the features it offers, then import it into Construct. Basically let Rive handle the UI side (which from what I've heard it's great at) and let Construct handle the game part.
So your plugin allows Rive to interact with C3 events? That's pretty cool!