Nyet

Nyet is a freeware Tetris clone using ANSI graphics. The following was taken
from the game’s readme file:

Although I did not invent the game, I did write this implementation from
scratch (using Turbo Pascal Version 4.0). I did it mainly for the hell of it,
but I improved on the original where I thought it needed it. The two main
improvements are the ability to run on monochrome screens (although it looks
better in color) and a more responsive feel. Finally, my version should work
at the same speed no matter how fast your processor is; I have heard that that
is a problem with the commercial version.

Nyet