I've been playing the game pretty much solid all day and I just got into the 32 cube door (28 Cubes and 4 Anti-cubes), went through the stargate and then everything went batshit crazy. 
 
I got the credits and I got the finished achievement and then when I went back to the start all I can do is start a new game or new game plus. I started new game plus and got my first person sunglasses. Awesome.
 
So now what? Do I just now need to spend the rest of my life trying to solve these super cryptic puzzles, backtracking all over the place until I finally solve them all and finally get all the anti cubes and get some sort of true ending? Because I don't really want to do that. I mean I really enjoyed this game but there was so much stuff in there that just left me clueless. I still have no idea what to do with the bell or the big owl statue that follows you around or the weird light up tetris thing or that single tree sitting on its own in the middle of the lake or all the random coloured pillars or that strange jagged line symbol that seems to appear everywhere or the telescope that for some reason gave me half a red cube that isn't even in my inventory . Do I need to somehow learn what all the symbols and signs are saying, is there some sort of code I need to crack (i assume so, given the achievement)? Do I need to to be able to read the fez alphabet before I can solve all the puzzles? Does that involve the writing artefact I found which is just some weird dice? 
 
THIS GAME MAKES MY HEAD HURT.

I think this game expects you to be smarter than you are. This post pretty much perfectly summed up a lot of my problems with the game. The fact that (spoilers) the way to figure out the alphabet is to look at a drawing of a fox-like creature jumping over something next to some symbols and figure out that it's referring to the lazy fox jumps over the thing English phrase is pretty ridiculous (and seems like a thing that would be even harder to guess in other territories). It's so cryptic it borders on absurd. Braid was hard, but at least you always knew you had everything you needed to solve a puzzle. Here, the solution might be a couple of symbols in a room inside a room inside a room inside an invisible door that's underwater.

ART!!!

Yeah, and to do everything, you're definitely going to need a pencil and journal.

The key to the owl is to get behind its head. That is to say, get it to be looking away from the camera instead of towards it.

I'm personally glad this game actually does test your ability to think further than most games dare to do. Haven't solved it all yet of course but I will sooner or later.

Played this pretty much all day. Got all 64 cubes and just finished my NG+. No "true ending" still, because there's one puzzle at the end that apparently only a whole one person has solved so far...one of the sound engineers for Fez.

There is a NG++ and another "ability" that unlocks with it. I'm hoping that is the key to the last puzzle. If that puzzle is anything like the security key, I'm not really counting on being able to figure it out easily.

This game has been refreshing, though. It has been a while since I've seen a good head-scratcher that has forums abuzz with people working together to figure shit out. Shame it's just an arcade title. We could use some bigger games like this.

Some of the puzzles have just bad design. For example, I was only able to figure out the input puzzles after I started using bigger TV and was actually able to see the symbols. I don't speak English as my first language, so "quick brown fox" was too great of a leap for me. Also after figuring out some puzzles, inputting the result was tedious.

I enjoyed the game but think that it would have been better if for example 1st person view would been available on the first run and there was better map or quick travel system.

Ending was brilliant.

I finished the game last night with seven anti-cubes and 25 regular ones and I feel the same way. I think that Fez has a difficulty problem where it expects you to follow along with incredibly minute details and clues without giving you reason or explanation for those clues to exist. For example, I spent hours outlining, drawing and going through the room with all of the doors in Ghost Town twice before I gave up and looked for a hint online, and found out that you needed four treasure maps to complete it. So, I got the four maps, came back, but since I don't know the language I don't know what the symbols and the room remains uncompleted. After all of that fuss, I don't think I'll bother.

There's a difference between puzzles that give you all the information you need to solve them upfront and ones that require you to backtrack to places where you don't know where you're going. Don't get me wrong, I think Fez handles the former brilliantly (I solved one of the Tetris puzzles using, no joke, Chex Mix) but on the latter it stumbles a little since the designers can't quite convey how much you're supposed to know about tis world versus how much you can infer.

I did get a chuckle at the QR code, though. That was pretty amusing.

I knew Fez was supposed to be a puzzle game, but I thought it would be more about playing with 2D/3D environment in clever ways than decoding random shit. I mean, you certainly play with rotating the world, but I feel like it never exploited the mechanic to it's full potential, so the all the puzzles, if you can even call them that, involving it sort of solved themselves. What you're left with is a bunch of challenges that don't engage what makes the game unique, and are thus uninteresting. It's like if Portal or Braid only used portals and time manipulation, respectfully, for traversal, and the puzzle solving was limited to deciphering the Ratman messages or story books.

@Slaker117 said:

I knew Fez was supposed to be a puzzle game, but I thought it would be more about playing with 2D/3D environment in clever ways than decoding random shit. I mean, you certainly play with rotating the world, but I feel like it never exploited the mechanic to it's full potential, so the all the puzzles, if you can even call them that, involving it sort of solved themselves. What you're left with is a bunch of challenges that don't engage what makes the game unique, and are thus uninteresting. It's like if Portal or Braid only used portals and time manipulation, respectfully, for traversal, and the puzzle solving was limited to deciphering the Ratman messages or story books.

Good sum up.

I wish there was more "game".

It's a beautiful game, and the music is utterly brilliant. Why put so much effort in to puzzles that are cryptic instead of exploring the gameplay more? It's cool, Polytron obviously wanted to make the game this way, he's been at it long enough. I just feel like, gameplay-wise, it doesn't reach the pinnacle of Portal/P2.

While I agree with a hole bunch of everyone who stated that the game's difficulty/learning curve is insane and that it demands too much from the player I feel it adds a nice touch to the game. While I didn't figure out the language or the numbers on my own once I understood the game became a hell of a lot easier. The point I'm still trying to reach here though is that deisgning the game in that way, having its own language and numbers etc added to the overall feel of the game. It made the world Gomez inhabited feel more alive, gave a sense of history and life that most games struggle to create.

And the ending... awesome.

@itsVASH said:

While I agree with a hole bunch of everyone who stated that the game's difficulty/learning curve is insane and that it demands too much from the player I feel it adds a nice touch to the game. While I didn't figure out the language or the numbers on my own once I understood the game became a hell of a lot easier. The point I'm still trying to reach here though is that deisgning the game in that way, having its own language and numbers etc added to the overall feel of the game. It made the world Gomez inhabited feel more alive, gave a sense of history and life that most games struggle to create.

And the ending... awesome.

The problem here is that these puzzles are really only solvable via the internet if you aren't some kind of genius decoder that can spend a lot of time paying attention to minute detail.