City of Scars

City of Scars is a 2010 fan-made short film about Batman and set in the Arkham Asylum. Created by a long-time Batman fan with a budget of $27,000, it was shot in 21 days. It's a remarkable film, both in how faithful it is to the characters and the universe and in how well it's done on a limited budget. If you're not already a fan, I doubt this will convert you; but it's a fun addition to the character.

via Youtube:

There is a 2011 sequel, Seeds of Arkham, shorter at 8 minutes:

via Open Culture, where they say, "City of Scars, and its 2011 sequel, Seeds of Arkham ... have garnered a generous helping of attention and awards (The Wall Street Journal called City of Scars “impressive”)".