Looking for an old pc game name !?

[Behzad]

For all ya old schoolers out there I am looking for a game but can't think of the name... Basically your this little square thing that goes across the bigger box your playing in with enemies inside, and as you Make the BIG box smaller and trap your enemies in it, your level finishes once u got rid of all the enemies.. its old and 2d if im not mistaking , It makes the box smaller and smaller