Introduce an instance variable
SQ_MOVEMENT.
_________ | Set SQ_MOVEMENT to floor( Time % 4)
This will cause SQ_MOVEMENT to be reset 0,1,2,3,0.... infinitely.
Then give it a custom movement,bullet or use lerp for each state.
Decide which one you'll use then do this:
SQ_MOVEMENT = 0 | [Move Right]
SQ_MOVEMENT = 1 | [Move Down]
SQ_MOVEMENT = 2 | [Move Left]
SQ_MOVEMENT = 3 | [Move Up]