Pressing 'T' turns the sound on or off - but only while a game is in progress (see 698E).

In addition to the documented movement keys - 'Q', 'Z', 'I' and 'P' - the keys '1', '2', '3' and '4' can also be used to move Horace left, right, down and up (see 62C4).

When Horace moves from maze 4 back to maze 1, the game speed parameter at 7C62 is decreased by one, which increases the speed of the game (see 69A4). It reaches its lowest value (1) on the 29th maze, and then remains at that value until the game ends.

The bonus awarded for eating a cherry or strawberry depends on Horace's direction of approach. He scores 60 when moving up or down over the fruit (50 for the fruit itself, plus 10 for the green leaves, which count as a flower), and 100 when moving left or right over the fruit (50 for each half of the fruit).