Keybard shortcuts (hotkeys) help you do in-game actions using your keyboard without the need of mouse clicks. They are also convenient for use with macroing.

Key Action
C Big Crunch
M Max All
S Dimensional Sacrifice
D Dimension Shift/Boost
G Antimatter Galaxy
A Toggle Autobuyers

keys (1 - 8)

Buy 10 Dimensions (of the correspondingly numbered galaxy)