Remember how Journey to Silius was originally meant to be a Terminator game? Whether Sun Corp. lost the license or never had it to begin with, it would've made for an awesome game.

I wonder if a prototype is drifting around somewhere...?

Good question, dunno if someone actually has one. Maybe DreamTR would but i never heard of someone actually having proof on cart, i only heard of it.

Sadly, it probably doesn't exist - at least on cart form.  The only info on that is some blurb on Nintendo Power that states that they somehow got pics of it.

Read it also man, there's so many things to be discovered and unanswered.
My guess is it was destroyed in the process since Nintendo did that alot with pre production games not to mention software.
I try to track some things down but it's not easy, in most time your depending on others.