I also strongly disagree with the notion that a short game should inherently be priced lower than a longer one. $50, Star Fox Zero's price, seems quite reasonable for what it has on offer, and if you get it retail at $60, you get Guard, which may or may not be good but which looks like it has the potential to be good. (I'm not getting Guard, just Zero)
Is Zero perfect for me? No, it's missing some things I would like (especially a Japanese audiotrack), but I love gyroscopic aiming on 3DS and Wii U and I love arcadey score-attack rail shooters, so this game is basically the only game in town for me on that front.
The death of the short arcade-length beat-in-one-sitting play the same levels over and over as you hone your skills game is one of the worst trends in modern gaming. There were plenty of arcade cabinets that I put well over $60 in quarters into. Having a game of that style at home for a fixed price, like Star Fox, is a blessing.
We need more new rail shooters. I hope this game inspires some competition in this space.
I am so glad this game didn't end up as Star Fox Meets No Man's Sky, with free exploration and no rails. The end of having the player on rails through fixed location was the end of good level design, IMO. I want more games with no roaming or exploration, just action through setpiece levels with predesigned challenges.