I don't know! I really don't know. I spent a good 30 minutes with the software (in browser, sorry for not being a part of the download number). It felt more like I was playing around with something, rather than actually playing something. It felt like interactive art (which includes video games (maybe not all video games: kinetic novels??)), but not a video game. Is Godot Engine a video game? Maybe it is.
Out of the ideas you put forth, I think video games are closest to "your playful attitude when you interact with it." I don't think I had that here: I interacted with this software more via investigation rather than a playful curiosity. Perhaps that's my bad.
Either way, thought provoking work as always. I enjoyed my time with it; happy to engage with more in the future.