Well, after having my wife play the demo, she had to have it (the game I mean). So, I just wanted to add our thoughts on the game thus far.
We're currently about 25% into the game, and we both love it. The term "puzzle platformer" perfectly describes FEZ, as most of the puzzles require some platforming skills. As for games it reminds me off, it feels like a mix between 'The Goonies 2', and 'Alex Kidd in High-Tech World' (massive nerd points if you know that game).
As mentioned before, the art style and music are both superb. The soundtrack will be released on April 20th, and can be had for only $5! Well worth it imo.
In case you're wondering, there are different areas in the game which have different environments. Aside from the soothing sunny areas we've been to, we have also found lush forests, and even a dark and gloomy rainy world with lightening and thunder. The rainy world even had a Castlevania feel to it, with cross gravestones and whatnot.
If you get a chance to play this, do so. Games like this need to be supported.