Guess the Number is a simple command-line guessing game that is so old in concept I'm sure the wheels have fallen completely off, rotted away, and mixed back in with the atmosphere.
Still, it's my first video game (of sorts), so yahoo!
ruby play-guess.rb
Optional range for randomly-chosen correct answer can be supplied as a command line argument (defaults to 1-100)
ruby play-guess.rb 20 150
Good luck!