You never want the audience to roll their eyes when they read the title cards in your trailer. The use of subjective adjectives or nouns is one way you might be undermining the strength of your trailer or even setting up an adversarial relationship with your audience.
Here’s what I mean when I say “subjective title cards.” Imagine a trailer for a game with these title cards:
Amazing Multiplayer Action!
Incredibly Deep Gameplay!
Exciting Action Carnage!
Obviously, these are intended to puff up the game and excite the audience, but would it really? Does this trailer expect the audience to believe the multiplayer action is amazing simply because the trailer says so? Amazing to who? What constitutes amazing multiplayer action versus unamazing multiplayer action? What makes it amazing? The same questions can be asked for "incredibly deep" or "exciting" and there's no criteria which can be used for all people.
They're all subjective words, which at best are kind of empty. These sound like the trailer knows the gameplay needs some help, but all it can do is put on some words and hope the audience goes along with it. This is the trailer trying to tell the audience the game is cool instead of showing; it puts the trailer in a defensive position of trying to convince and sell to the audience. The harder sell is often the least convincing one, because anything worth purchasing would almost sell itself.
I generally think subjective words like this should be avoided, but there is a caveat. If a trailer is going to use subjective words in its title cards, the audience better be 100% in that head space already. Or maybe the game has a good sense of humor, so when those superlative words pop up, the audience knows it's being told in a tongue-in-cheek fashion. I think most trailers won't have the right tone necessary to use this kind of subjective language, and any game worthy of this kind of hype wouldn't need it anyway.
This applies to movie trailers too! Imagine movie trailers with title cards which say:
A heart wrenching story about...
An emotionally gripping tale...
An unparalleled action adventure!
The same ideas apply. Why would we take the trailer on their word that the story is any of these things? At worst, this sort of wording gives the audience an: "Oh yeah? PROVE IT!" attitude. They might start looking for ways the movie or game is not the things it describes itself as.
Just imagine a man stating: "No one is a greater supporter of women than me!" How many people would take this person at their word? More likely, they're going to start checking up on this guy to find all the instances which contradict this haughty statement.
Keep in mind, this mostly applies to trailer title cards which are not quotes. Press quotes are a way to circumvent the possibility of looking arrogant (assuming there are good press quotes to pull from). An audience will be more prone to be convinced if someone else's words are used to describe a game or movie in a superlative fashion with subjective adjectives.
So, avoid these subjective descriptors as much as possible in trailer title cards. If you think there's no other way to show the game is cool, then it's still time to investigate how to do it by other means. A hard sell trailer is easy to spot, and even if someone doesn't realize they're being given a hard sell, I think they'll still understand that what they're seeing isn't making a convincing case for itself.
What is the answer for good title card text? I talked about it a bit in this post about title cards, but for a more in-depth look around the language to use about your game, one of the GDC talks I did this year with my friend Dana Trebella is precisely about messaging, and finding the right words to describe your game. It's now on the GDC Vault and available to the public.
While you're at it, check out my other GDC talk from this year about making game trailers which is also available to the public!