You can clean up some of the code. for example change:

alias endgame2 {
  .timerpong off
  set %gameover 1
  drawtext @pong 0 Algerian 150 195 200 Game Over
  drawtext @pong 9 Tahoma 50 330 410 Left wins! Score: $calc(%points * %speed)
  drawtext @pong 0 Algerian 30 300 470 Press spacebar to restart, or Q to quit.
  halt
}
alias endgame1 {
  .timerpong off
  set %gameover 1
  drawtext @pong 0 Algerian 150 195 200 Game Over
  drawtext @pong 4 Tahoma 50 330 410 Right wins! Score: $calc(%points * %speed)
  drawtext @pong 0 Algerian 30 300 470 Press spacebar to restart, or Q to quit.
  halt
}

TO:

alias endgame {
  .timerpong off
  set %gameover 1
  drawtext @pong 0 Algerian 150 195 200 Game Over
  drawtext @pong 9 Tahoma 50 330 410 $1 wins! Score: $calc(%points * %speed)
  drawtext @pong 0 Algerian 30 300 470 Press spacebar to restart, or Q to quit.
  halt
}

And then just type /endgame [left/right]
Instead of putting a separate alias for both.