Dragon Quest
A simple text adventure (or work of interactive fiction) written in C++. You've got to kill the dragon, a task you can only achieve with the help of various artefacts you've got to collect.
Get the source from here, compile it with "$ g++ dq.cpp -o dq", change the binary's permissions with "$ chmod 751 dq" then run it with "$ ./dq".
Good luck!