Snake is a project mainly written in C, it's free.
A simple VT100 snake implementation
Michajlo Matijkiw
This code is neither pretty nor heavily tested, but it's great for killing time.
list.c/.h are very general implementations I created back in school, so a lot of the code probably isn't used here.
I know curses could be used, but my goal was to get familiar with VT100 codes. I may port it to curses later.
If the score is coming up within the bottom wall, then your terminal probably isn't big enough.
Possible improvements:
To change the speed edit the value passed to usleep (search for it, theres only one).
To change the size, change the #defines at the top of the file.
Share with friends and family, everyone gets bored.