Autorun halts and goes back to desktop after a few minutes

Bullseye with Matt's setup.  I am a Linux noob and trying to build this for my daughter (post-grad student at MIT) for a Christmas present.  I have tried various ways to autorun the .sh script.  I tried the exact way that the OP did, I did the system.d method too.  I can't seem to get it to keep running.  