The ← and → keys move the blocks across the screen.
The ↑ key rotates the block. The rotation (which is counterclockwise by default) can be changed in the Preferences.
The SPACEBAR and ↓ key increase the speed of the drop. The SPACEBAR causes a hard-drop (instant move to the bottom). The ↓ key causes a soft-drop (temporary increase in speed while the key is held down).
There are a couple of rules that you should keep in mind:
You can pause, end, start a new game, get help or quit the program at any time.
You can pause the game as many times as you want.
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