Exactly 25 years ago, a little desk lamp pounced on a rubber ball and accidentally deflated it. The lamp sadly hopped away, only to return seconds later with an even larger, more impressive ball. In a way, Luxo Jr., which premiered at a Dallas computer-graphics conference called SIGGRAPH on Aug. 17, 1986, is the perfect metaphor for the then-fledgling studio that created it: Pixar. The short film announced the arrival of a new player in the animation scene, but Pixar had much larger toys waiting in store.

On the 25th anniversary of Pixar’s first project, it seems appropriate to consider exactly how the studio has altered the world of animation. A lot of Pixar’s success — its 12 feature films have received 40 Oscar nominations and earned more than $7 billion in worldwide grosses — can be traced to its emphasis on story and characters above all else. An argument could also be made that the studio’s distance from Hollywood — its campus is located in the small San Francisco Bay Area city of Emeryville — helped foster its independent spirit and out-of-the-box thinking. But the company has enriched the medium of animation in a number of other ways, too. Here are five examples of how Pixar has improved the animated feature film:

1. Slowing things down

I caught parts of Disney’s Beauty and the Beast and Aladdin on TV last weekend. Both are cherished movies of my childhood, but what particularly struck me while watching them now was how rapidly paced they were. Aladdin, in particular, was akin to being trapped in a pinball machine. The picture’s a lot of fun, but it’s always in a rush to get to the next action set piece, the next musical showstopper, and the next Robin Williams impersonation. The film considers its audience an extremely impatient bunch, so it never stops trying to razzle-dazzle us.

Pixar, on the other hand, knows the value of temporarily slowing down a movie’s narrative. The studio had faith that its audience, children included, wouldn’t lose interest during Up‘s wordless montage depicting the marriage of Carl and Ellie Fredricksen, or during the eerie opening scenes of WALL-E.

Furthermore, Pixar has no problem making movies that are longer than most animated films. During the “Disney Renaissance” (from 1989’s The Little Mermaid to 1999’s Tarzan), Disney’s longest animated movie was Hercules at 93 minutes. But Pixar approached nearly two-hour runtimes with Cars (117 minutes), The Incredibles (115 minutes), and Ratatouille (111 minutes). By no means is a longer movie necessarily better than a shorter one — Cars could have been trimmed some — but Pixar’s willingness to even make animated features of such lengths is refreshing. If they feel their story is deserving, they’re going to take their sweet time.

2. No musical numbers

I hesitantly list this reason, as I’m as big a fan as any of Disney songs. But like a shorter runtime, musical numbers in animated movies often feel like a concession to kids, who apparently require something to tap their toes to every 10 minutes. By not having its characters suddenly break out in song, Pixar could pursue subtler ways to flesh out its characters. Could you imagine The Incredibles or Up working quite as well if Elastigirl or Carl Fredricksen started belting a tune about how hard it is to be a stay-at-home mom or a heartbroken old man? (“My neighbors think me a cranky barbarian / But I’m really just a sad septuagenarian!”)

Yes, I know Pixar has featured the occasional song, such as Toy Story‘s “You’ve Got a Friend in Me” or Toy Story 2‘s “When She Loved Me.” But these numbers served more as narration for a montage sequence than as an opportunity for characters to put on a show for us.

3. Refusing to flaunt its celebrity voices

Pixar’s not against using the voices of big-name celebrities, such as Tom Hanks, Owen Wilson, Kevin Spacey, and Ellen DeGeneres. But unlike rival studios, Pixar doesn’t advertise its stars (or give them above-the-title billing, a la Shrek). “I don’t want people to go, ‘Oh, isn’t that so-and-so’s voice?'” Pixar head John Lasseter told EW. “We do have great actors, but we want people to be swept away with the story and the characters.” One gets the sense that Pixar casts whomever the studio thinks is most appropriate for a role, regardless of that actor’s drawing power at the box office. How else can you explain the casting of Patton Oswalt as Remy in Ratatouille, or Ed Asner as Carl in Up?

4. Having the courage to tackle tricky subjects

An Earth devoid of humans in WALL-E? Suburban marital strife in The Incredibles? A 78-year-old adventure hero in Up? Pixar relishes the opportunity to tackle difficult stories — material that’d send most other studios running. Animation was once relegated to fairy tales and talking animals, but Pixar has opened the medium up to previously unexplored territory. Here’s hoping they don’t suddenly get cold feet.

5. Raising the bar for every other animation studio

Without Pixar setting such a high standard, I wonder if we would have had How to Train Your Dragon, Rango, Kung Fu Panda, and Happy Feet. Those pictures can’t touch Pixar at its strongest, but they’re still delightful (and at times beautiful) pieces of cinema. I can’t prove whether having a high-achieving student in the classroom lifts the performance of all the other students — chime in if you’re a teacher — but it couldn’t possibly hurt.

Before Pixar, an animated film had never received an Oscar nomination for its writing. Now it has happened eight times, thanks to seven Pixar movies and DreamWorks’ Shrek. Whereas before a studio might have said, “That idea is too outré or sophisticated for an animated feature,” now that studio can look to Pixar and say, “If they can pull it off, why can’t we?”

Where Pixar goes from here…

The studio may be at a defining juncture. By the time the Monsters Inc. prequel Monsters University opens in June 2013, three of Pixar’s last four projects will have been based on preexisting films. One of those films, this summer’s Cars 2, became the studio’s first picture to receive mediocre reviews.

Pixar obviously knows how to make sequels work (see Toy Story 2 and, especially, Toy Story 3). But I worry that they may never repeat that envelope-pushing streak of Ratatouille, WALL-E, and Up. I worry when I see someone like Andy Hendrickson, Walt Disney Animation Studios’ chief technical officer, reportedly say that visual spectacle — not story — should be the focus of Pixar’s parent company.

But then I see the stunning trailer for Brave, Pixar’s summer 2012 release, and I feel silly for worrying so much. Here’s a movie starring a female protagonist (the studio’s first) and set, of all places, in the Highlands of Scotland. Here’s a movie in which the lead character was once going to be voiced by Reese Witherspoon, and is now being played by the much less commercial (and much more Scottish) Kelly Macdonald. And now I’m a little desk lamp all over again, eagerly awaiting Pixar’s shiny new present.