I saw a website advertising this play awhile back.I wasn't sure what to make of it or how they'd adapt the story for a stage play.By the looks of the descriptions and reviews I read here along with some of the photos,it looks like it stayed true to the tone of the story.
People have tried to adapt movies into plays before and sometimes it didn't work too good.I saw Titanic (the Broadway play)in the late 90's while visiting New York..hoooo boy

they shouldn't have done that.
Because of that one bad experience seeing the Titanic play,I started to chuckle at the thought of Oskar & Eli tap dancing in unison, side by side to high paced Charleston music in Eli's apartment during the "Are you a vampire?" scene.Oskar spins and does a "Ta-Da" gesture with his hands and knocks the puzzle egg over.
Reading these comments though, I can appreciate the folks who made the LTROI play.It sounds like they did it right.
Wish I could have seen the play myself.

Heres an older link I found with a write-up and short video of the stage play.
http://www.vampires.com/let-the-right-one-in-on-stage/