The Silent Hill 3 UFO ending brings Harry (and James) back, along with an entire flying saucer armada, to destroy the whole town with lasers. (The credits further feature a nonsensical song that proceeds to describe the main characters in completely inaccurate terms, and ends with the singers dying in a hail of machine gun fire.)
The Silent Hill Origins UFO ending has Travis hitchhiking his way out of the town (and the Solar System, at the very least) curtesy of a friendly alien and a suspiciously familiar shiba inu.
The ''Silent Hill: Homecoming UFO ending has the protagonist and his Love Interest abducted by aliens while the Token Minority character watches on in amazement, exclaiming "I knew it!" And you can blunder into this ending entirely by accident, as opposed to going out of your way to get it, adding to the WTF factor.
Silent Hill The Arcade can end with the Big Bad flying away in a UFO, and one of the heroes giving chase in a VicViper...zoom out to Robbie, playing on an emulator.
Shattered Memories has the biggest Mind Screw UFO ending of all time: Cheryl claims her father was abducted by aliens, saying Silent Hill is really a giant spaceship, then James comes into the therapist's office having gotten the day of his appointment wrong (he's one of Kaufman's couples' therapy patients; Kaufman notes how he hasn't seen his wife recently), then the camera zooms back to Cheryl, who's turned into the shiba inu dog and begins talking about how her mother was a bitch to Dr. Kaufman, who has turned into an alien. James can be seen hiding behind the sofa, and various items from the series are seen on the shelf.
Silent Hill: Downpour has Murphy tunnelling his way out of Overlook Penitentiary when he emerges into a darkened room, whereupon the lights come on and "SURPRISE!" is shouted. In the center of the room is a birthday cake and James, Laura, Anne, Sewell, Heather, two Silent Hill 2 nurses, Mary, Ricks, the boy from St. Maria's and Frank Coleridge are present to celebrate Murphy's birthday. Then Pyramid Head emerges from the shadows with his Great Knife to cut the cake, but also slices the entire table in half.
FIFA 11 allows you to play goalkeeper for the first time. Explaining: even when you play as your whole team, you usually don't get to do much with your goalie since the AI does pretty much all the saving for you. Playing goalie, though, you obviously have to do all the work.
NHL Hockey: NHL '09 introduced the "Be A Pro" mode, where you're tasked with accomplishing various objectives to help your team win the game.
The Pure White Glastonberry Extreme segment of No Moreheroes does this, coming out of nowhere, having no significance to the plot, just something Travis did with his time on the way to a ranking battle.
Little Inferno is all about finding right item combinations to burn based on wordplays and other hints in a puzzle game almost as detached from a character perspective as Tetris. Then, in the final segment your house burns down and you unexpectedly start guiding the previously unseen player character from a fixed third person perspective through snowy streets, talking to people and trying to make sense of the past few hours (implicictly months if not years in story time) and your own motivations for playing the game.
Freddy Pharkas: Frontier Pharmacist: The first act of the game is prepping medicine for townsfolk, then using your mad medicine skills to save the town from various disasters, but after that Freddy returns to his gunslinger roots and all puzzles are solved with gunnery.
The Pokémon community Showderp is this to the competitive battling scene as a whole, with a majority of its teams consisting of things you would never see in standard play.
Ultima VIII is totally different from his predecessors: in addition to being Darker and Edgier, it's far more "arcadey" in style (jumping puzzles are very common), is set in a completely different world (Pagan instead of Britannia) without the usual magic system, the Virtues are not present, and the Avatar is alone, without his usual True Companions.
Xeno Gears sparked something of a tradition in the Xeno series of having the first scenes take place long before the plot of the games themselves, with the connection only being revealed much later on. In this game's case, the opening scene is of a ship that is taken over by a mysterious force that prompts the captain to self-destruct it. A couple scenes later, we're introduced to a painter in a backwater town living peacefully, and things pick up from there. While the ship is relevant to the game's overall plot, the actual relevance isn't explained until much later, and only a couple of the characters from it reappear at all.