Out of any software tools I use frequently, Unity is the one that brings me the most joy. Any reasonably complex interface is essentially a game whether it's a music composition app, simulator, MMO or even a basic form. The basic abstractions of entities and components sometimes feel like they could apply to any software project. It's seamless to animate something, add physics, style in ways that would seem mind bogg…
I remember this boat in early 2000s, when engines were less capable, and I was younger and more arrogant. The thought of using some crappy engine with last gen graphics would make me laugh. Of course I was going to make my own thing in C hand-optimized to squeeze every last triangle from the hardware. Good luck if you didn't have that exact hardware configuration :)