LESS IS MORE: “A Wonderfully Difficult Journey,” based on The ARC Mercer, is among the short films being presented May 20 and 21 at the third annual Nassau Film Festival.

It didn’t take long for word to get out about the Nassau Film Festival. In just three years, the annual spring celebration of short films has blossomed from 35 submissions in 2015 to 336 for this year’s event, which returns to the Princeton Garden Theatre May 20 and 21.

Forty entries will be screened over the weekend. This expanded schedule will include the work of budding filmmakers from all over the world as well as local students, some of whom were winners of the Walnut Lane Student Film Festival. Several of the foreign filmmakers will be in attendance, traveling from as far away as Brazil, Canada, and the United Kingdom.

“It’s quite remarkable,” said Lew Goldstein, the festival’s director, whose day job is assistant superintendent of Princeton Public Schools. “People know now that it’s a good festival that is specific to short films. We had entries this year from Iran, Senegal, Australia — all six continents.”

Mr. Goldstein and publicist Dan Bauer co-founded the festival after noticing that short films were not a part of the local cinema scene. “I’m a filmmaker, and it was after I did my own film that I realized this,” Mr. Goldstein recalled. “I thought, wouldn’t it be a great idea to have a festival around short films? There are some great short films out there that are better than some Hollywood-produced movies. We have one film that is one minute long, done by a 10-year-old girl. It’s really cute. So not every film is super serious. Some are mysteries. There’s a great variety.”

Animation shorts are a part of this year’s mix. There are documentaries and other features, some by local filmmakers including Communiversity by Syth DeVoe; A Wonderfully Difficult Journey about developmental disabilities and the agency The ARC Mercer, by Kirk Pointon; and Passage of Hope, about mental health and the work of the National Alliance of Mental Illness (NAMI) by Tom Pyle.

Short films are also the subject of the Trenton Film Society’s annual Oscar Shorts festival which screens Academy-Award-nominated features at the city’s Mill Hill Playhouse each February. The fact that they hold a category all their own is testament to these films’ unique characteristics.

“They tell a story in a time frame that people with short attention spans can appreciate,” said Mr. Goldstein. “And they are very, very powerful because they are required to tell a full story in a limited amount of time. You have to be crisp on sound and on cinematography. And you have to be able to write the story succinctly. To do all those things well is really a great talent.”

Credit for the festival’s growing popularity goes, in no small measure, to its student participants. “With social media, they get word out faster than anybody,” Mr. Goldstein said. “I think by opening it up to student filmmakers, the word spread quickly.”

Seven people with film backgrounds served as judges for next weekend’s event. “It was really hard to narrow it down,” Mr. Goldstein said. “They were looking at various categories like editing, sound, cinematography, and screenplay. I think everybody had different opinions, but everybody felt that all of the films submitted were of really high quality — even those from students.”

This year’s addition of animation to the existing categories of documentary and fiction speaks to an effort to expand the scope of the festival. “We didn’t want to set parameters on what filmmakers can send us,” Mr. Goldstein said. “We like to see creativity. We like to see vision. We want them to know we appreciate their individual talents and want them to submit whatever they feel is their best work.”

Admission to the Nassau Film Festival is free, as are popcorn and refreshments. Times are 9 a.m. to 3:30 p.m. Saturday, May 20; and 9 a.m. to 12:30 p.m. Sunday, May 21. The Princeton Garden Theatre is at Nassau and Vandeventer streets. Visit nassaufilmfestival.org.