These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Never Live It Down: Judging by comments about The Last Guardian, the team has gotten the reputation of having Downer Endings... despite the fact that out of the two games they've made, one has a clearly HappyEnding, and the other is Bittersweet. This explained by both games' overall tearjerking catharsis process.
Word of God for ICO: "In Japan there's this saying, 'when it ends well everything's well'. My theory was to already in the beginning of the game make the player understand how important the ending would be. Then the player would strive to reach it, it would keep up motivation the game through. Because I believe that the only purpose that games have is to enrich the hard life we live. And that's why ICO got a happy ending." This basically means that the games will always be solidly on the Idealistic side of the scale.
Sacred Cow: Because of their status as works of art, few dare to criticize the games.
Tear Jerker: The overall mood in both of the so-far-released games is nothing you could call "Light Hearted"
The back-story in ICO is pretty depressing even if the ending is fairly happy, and it certainly puts you through the wringer from beginning to end.
If you don't feel something at least once after finishing off a Colossus, you are a horrible person and probably kick puppies. If you play all the way through Shadow it's a Bittersweet Endingat best.
Judging from the trailers for The Last Guardian the packaging might as well come with a gun and a bullet with instructions that say "For your heart."
Values Dissonance: Fumito Ueda changed the protagonist's gender from female to male in The Last Guardian, citing climbing mechanics requiring physical strength as one of the reasons despite female athletes regularly displaying physical prowess. His other reason was to avoid upskirt shots, seemingly never being exposed to a girl wearing pants in his life, or even leggings.