If you want to play a new game that takes advantage of the newest hardware, then there's never going to be an alternative to the PC or big consoles (Sony,MS,Nintendo). By the time Amiga can come up with anything these days, it's already been superceded years ago by all the big companies.
I think Amiga people should stop trying to out-do the PC and consoles at what they're built for, and focus on making the Amiga do what it's best at. What makes people like 3D games so much anyway, I preferred playing games back when they were 2D and that's what Amigas did best.
And Amigas always encouraged creativity. When you use an Amiga, it's fun, there are lots of things to do and things to make. Market to the creativity market perhaps, not the games market.