If you're using the cupon, it's definitely worth $35, no doubt. But that's about the limit for what I would pay for it.
I went into nerd rage at first when playing this game, because the Metroid series was god to me. The original Metroid, along with the original Zelda, are the reasons I knew I was going to be a lifelong gamer.
The game is a solid B..... which is unfortunate because I went in expecting an A+, because that's the standard that was set. I had to step back, calm down, and start playing again, and realize "it's not bad at all", but it should never come to that with a holy trinity Nintendo game.
It's definitely the "Super Mario Sunshine" of the series.