So I just finished messing around with the Sonic X-treme demo (the one they apparently had trouble porting over to the Saturn), and it was pretty good! According to the Readme, the demo was in the process of a rewrite when it was dropped, and it was still very fun and I could see a lot of potential in it. 

I liked the camera turning mechanic, even if it was like a debug thing, they could've made some cool puzzle levels with it. Even though there was no music in it, I feel like a great soundtrack would've come out of this if it was finished. Also, the level design, although very basic and empty, had a decent start. 

I feel like if this was released, it would've been a real competitor to Mario 64 and it would've helped boost the sales of the Saturn. Unfortunately, that will always be a what-if. Maybe one day, someone will actually be able to finish Sonic X-treme.