nSnake is an implementation of the classic snake game with a textual interface. It is playable at the commandline and uses the nCurses C library for graphics. Its purpose is to provide a simply-coded, almost tutorial-like game with C. The source code is thoroughly commented.
yetris is a Tetris clone which runs on the terminal. It has colors and high scores, along with many features found on modern Tetris implementations. It's made with C and runs on (most) Linux terminals.