After spending hours in Xenogears undergoing hideous trials such as Babel Tower and Kislev's Absurdly Spacious Sewer, it is difficult to convey how disappointing it is to have entire dungeons and some truly epic-sounding battles narrated as recaps by characters sitting in chairs.
Considering Xenogears had some nightmarish 'dungeons', especially Nortune's Goddamn Sewer, that's something of a blessing.
Metal Gear Solid 2: The Big Shell falls apart as Arsenal Gear breaks free. Then a few hours later Arsenal Gear crashes into New York, causing even more destruction. But the master discs were burned on September 12, 2001 so it all happened off-screen, making the ending even more disjointed.
Not to mention Solid Snake, as a - well, as a concept. We get to play as him for two hours, if you play slowly and get all the Easter Eggs, And Now for Someone Completely Different! He runs around the Big Shell killing sentries left and right and doing crazy stunts to defuse bombs, and we have his word to go on, only. He goes off to have a showdown with a ninja, and the only indication of this we get is him telling Raiden that he has his hands full with something on his end, followed by another character explaining what had happened, later on. The raised middle finger of this whole aspect was very, very, very intentional.
Also, the opening cutscene of MGS2 explains that Solid Snake and Otacon traveled around the world for two years destroying Metal Gears as part of the non-government group Philanthropy. Considering that Snake has only starred in two full next-gen games (to date), was it too much to ask for a prequel game detailing the intervening years of their involvement with the group?
Fortune drags him atop Arsenal Gear in handcuffs. How did that happen? It was probably awesome. We probably would have liked to see that.
In Halo, the Battle of Earth as a whole is this trope. The actual massive battle takes place in between Halo 2 and Halo 3. Similarly, a lot of the massive battles of Reach happen in the background.
House of the Dead: Overkill plays this for laughs at the final boss. Then subverts it because you fight the final boss anyway.
Agent G: Varla, this is for you!
(MISSING REEL)
G: How we survived that, I don't know.
Washington: Hey, if we hadn't found these miniguns just lyin' around, we'd be fuckin' dead for sure!
In Dragon Age: Origins, the enchanter Sandal apparently slaughters an entire platoon of darkspawn. You arrive in the aftermath of this.
Sandal: Enchantment? You: What happened here? Sandal:Enchantment!
The first time, being much like the event in the first game, there's a giant frozen ogre, and Sandal's response?
Sandal: NOT Enchanment...
The fangame Paper Mario World sets up a boss battle... then not delivering any boss battle at all. To elaborate, Mario's allies just managed to free Mario from being trapped in a cave, but then Bowser shows up. All of them prepare for what what would be a third Bowser battle, but then a white screen shows up saying something like, "And then Mario and friends defeated Bowser." Then you see Bowser running away, and the others continue the game as if nothing happened.
In Assassins Creed Brotherhood: Ezio Auditore walks into the Rosa expecting to find his sister dead at the hands of the guards. Instead he finds that she killed a group of armed and armored guards with a knife, while wearing a dress, off screen.
In the "Fate" route of Fate Stay Night, Archer's standoff with Berserker is relegated to an off-screen bang, and Rin and Shirou's reactions. The anime fully renders the awesomeness, with perhaps more justice than the Visual Novel could.
Another one in the "Heaven's Feel" route, if you decide to let Rin kill Sakura. Kotomine predicts what's going to happen next and it sounds awesome - then you get a Game Over screen.
In Golden Sun: Dark Dawn this comes at the very end of the game when Alex goes off to fight Blados and Chalis off screen to give you time to save the world. Of course they all wind up surviving this little encounter. Camelot is quite skilled at never letting you know just how powerful this particular character is.
In No More Heroes 2: Desperate Struggle, Henry does Travis a favor by killing ranks 6 and 5, but the player doesn't get to control him (Despite the fact they just fought a Giant Space Flea from Nowhere in Henry's dream as Henry himself). In true ''No More Heroes'' fashion, the game then proceeds to call players out on their dissapointment, and Henry sends Travis pictures of him posing with their corpses to "Hold you over".
Although, it's thought pretty widely that the boss fights were supposed to be played, but got Dummied Out.
In ''Postal 2: Apocalypse Weekend,' there is a segment where the Postal Dude is asked to help "relocate pigeons," and he is handed a rocket launcher. The game immediately cuts to a video of the game's developer on the phone complaining that they don't have the money to make such a level. When the game cuts back to the Dude, he's standing in a massive pool of blood and feathers.
Dude: "Man, that was the most incredible thing I've ever done!"
Runescape features a quest called King of the Dwarves. Here's the rundown: the Big Bad is speaking to a mob demanding that the oligarchs who run the city reinstate the monarchy based on records of who is descended from the king. Meanwhile, his forces (only the character knows they are his anyway) are preparing an attack on the city to divide the guards. Your character and friends sneak into the record vaults and discover that said Big Bad is the rightful heir. The historical expert stays behind to forge the documents to keep Hreidmar from taking over while you and Veldaban go to help the city guards against his forces. You do so by tricking a troll warlord into doing it for you. And what does this epic battle look like? The troll warlord tells you to go back to the city and he'll take care of it.
Sam: And then there was the most epic battle of our entire career!
In Mass Effect 3, after spending the entire game gathering war assets and building an army, almost none of your war assets are seen or even mentioned during the final battle. This is one reason why the ending is so widely despised.
More generally, from the first game, it's been established that the Elcor fight by strapping massive clusters of heavy weaponry to their backs, and laying waste to their enemies using VI-targeted fire. They are referred to on several occasions as "living tanks". After three games, we still never got to actually see this.
We hear two different, unrelated stories about a Krogan battlemaster and an Asari commando tearing apart a space station in epic duels. Both times, the storyteller neglects to describe any parts of the battle itself.
One minor Fetch Quest involves finding a dinosaur fossil so they can be cloned and used as cavalry. As with all other War Assets, we never see the results of this.
