LTris is just another clone of Tetris but IMHO a good one, so if you like
Tetris, download and play it!

Features: 
     Tetris clone using SDL 
     Sound 
     Menu 
     Controls can be redefined 
     Block preview 
     Starting level between 0 and 9 
     Various backgrounds 
     HighScores 
     Nice graphics 
     Smooth gameplay 
     Cool effects (transparency, animations) 
     Two player mode 
     Two game modes 

Two game modes?  Yes.  The "normal" mode is the one everbody knows well.  You
play as long as you can while the blocks are getting faster.  The second one
called "advanced" has some additional features.  First there is a new figure in
each new level and second later on there are suddenly appearing tiles and rows.

WWW: http://lgames.sourceforge.net/index.php?project=LTris