Not really a game, but playing Minecraft has made me wish for real-world modeling software with a similar first person interface. Select from standard off-the-shelf components, use real-world tools, and craft stuff. Then test it out. I’ve got ideas in my head for all kinds of stuff, but going from there to an actual model is tedious with standard CAD and modeling software. Why can’t I (virtually) take an 8’ Douglas Fir 2x4, cut it with a saw, drill some holes in it - you get the idea. I could make something like a shed, then stress test it in a windstorm, pile 4 feet of snow on it, or drench it with rain. Or build a go-kart and see how it would perform. Tweak the design until it does what you want. Make the app user moldable and let the community go wild adding capabilities and virtual materials. Maybe it could eventually generate real parts lists, fabrication data for 3D printers and CNC machines, and assembly drawings.