Apple2Mac emulates a US ASCII keyboard layout that came standard with the Apple //e machine shipped in the United States in the '80s. This keyboard generated both upper and lowercase ASCII input.
NOTE: many Apple //e games were also designed to work with the older non-enhanced Apple ][+ machine which only allowed upper-case keyboard input (and also did not have up/down arrow keys). If a game does not respond to typing, make sure you have CAPSLOCK on.
NOTE: Some games required you to press the K key (or Ctrl-K) to engage keyboard input. Similarly if you desired to use the Joystick (including the Apple2Mac emulated keypad joystick) you would press a 'J' (or Ctrl-J).
For those of you who do not remember the '80s—lookin' at you Millenials!—there were a few keyboard "standards" that you could expect a game to honor (if playing via keyboard and not joystick). Some games allowed in-game key configuration, but others:
The Apple //e keyboard had an OpenApple and ClosedApple key which doubled as Joystick button 1 and 2. These are emulated by your left and right ALT keys, respectively.