Did Shakespeare perform in any other plays than his own?

Yes, Shakespeare is known to have acted in several plays other than his own. He was a member of the acting company called Lord Chamberlain's Men (later known as the King's Men), and during his acting career, he is mentioned in a few stage performances:

1. Ben Jonson's play "Every Man in His Humour" (1598): Shakespeare played the role of Knowell.

2. Thomas Nashe's play "Summer's Last Will and Testament" (1592): Shakespeare had a relatively small role that involved being killed onstage.

3. John Marston's play "Antonio and Mellida" (1599-1600): Shakespeare played the minor role of the character Hieronimo.

4. Shakespeare also played the title role in Ben Jonson's "Sejanus His Fall" (1603) before the court of King James I at Whitehall Palace.

While most of Shakespeare's acting took place in his earlier career, these appearances showcase his multi-faceted involvement in the theater as an actor, playwright, and theater shareholder.