Who can write the best story in under 15 minutes?
Why bother? Limitations are useful until they’re too limiting. The best story written in under 15 minutes is impressive for being written in under 15 minutes. That kind of limitation puts a limit on quality. A story can only be so good if it’s written in under 15 minutes. A useful limitation is not too constraining.
Use every technique that you know of. Use every word. Show off. Who’s stopping you? The stage is yours. Except that this too puts a limit on quality. A useful limitation is not too freeing.
The visible boundaries of your medium aren’t the only useful limitations.