I didn't mean that Super Mario was a complex challenge lol, any simple game would have done, the simpler the better. What I wanted to test was the visual/performance aspect. Besides, Super Mario is the quintessential platformer—if you can make a 3D version of Super Mario and make it look good, then you can make any 3D platformer. That's usually how I test engines; I don't complicate things with prototypes, I do what I already know well so I can focus on what I'm actually interested in testing 😝
When I have time, I'd like to take a look at Defold, since apparently you can already do interesting things in 3D with it, and I'll probably end up doing something similar.