There is just one arrow!
In an 8x8 world (that wraps around)
Click and drag corners to place doors.
Click and drag doors to place routes.
Click a route to cut it.
Click and drag routes to change time travel.
Click a door to record its noise.
Click an arrow to select it?
Click a cell to deselect the selected arrow.
Scroll up = zoom in to selected arrow?
Scroll down = zoom out of current arrow world.
When an arrow moves, it plays out what is inside it on that step.
You can make arrows bigger/smaller by putting them through bigger/smaller doors.
Smaller arrows travel faster, but move less far. eg:
2:1 door would make an arrow go double-time
3:1 door would make an arrow do the waltz.
Make an arrow go through a door with two routes to duplicate it.
Make an arrow go through a door with no routes to delete it.
If the last arrow dies... a new one appears in the middle.
Every new arrow has a different colour.
When you go into an arrow - the gridlines are the colour of the arrow.
By the way, you can also zoom out from the top level.