Even if you haven't paid much attention to computer games over the last 10 years or so, you may still have seen one of the trailers, possibly even on television. You may even have initially mistaken it for an animated movie trailer. Here's one from Dungeon Siege II, a now well-aged kill-everything-to-save-the-world game. (The music, incidentally, is by the critically acclaimed Jeremy Soule).
If you had bought the game soley from this 2003 trailer, I think you would have been profoundly disappointed. Only two or three scenes happened to you in the game, but as non-interactive cutscenes. One or two more happened to someone else. The rest of the exciting snippets (or were they made exciting by the music?) didn't make it into the game. And none of the scenes showed actual gameplay.
The in-game models looked like the models, but were a lot chunkier. Mood-wise, the game didn't come close to whatever stories were hinted at by the provocative scenes. Even so, it looked good for its time and had innovations for its genre, and was worth playing.
Nowadays, the trend has moved toward using "in-game assets" -- the models you actually see in the game -- to make cutscenes.
You can see some of the in-game cutscenes and movies on YouTube, but they are best viewed in BIK files played using BINK. BIK files can be converted into other formats, but the quality usually either diminishes or the resulting file is huge and strains system resources.
You can download some of them here:
Dungeon Siege II
- Background Story part 1 part 2
- About the Endtime part 1 part 2
- Dropships Approaching Greilyn Beach
- At the Dryad Temple
- Valdis Asks for the Aegis
- A Dragon at the Siege of Snowbrook
- Kalrathia fly-over
- The fortress, "Zaramoth's Horns"
- End of Valdis part 1 part 2
Dungeon Siege II: Broken World