A Common Lisp programming challenge along the lines of "Perl quiz of the week" or "Ruby Quiz". Each week a new quiz is sent to a mailing list, and users can send their solutions. A summary describing ...
GAMEYLISP, "A development diary for writing a Minesweeper game in Common Lisp using the Allegro games library", is Damyan Pepper's blog.
The Game - Yet Another Lisp Newbie Example
A tutorial which describes how to write a little grid game in Lisp (using the LispWorks CAPI toolkit for the GUI part)