Critter

Start with a simple critter.

Make a variable called critter with x and y parts.

Draw a dot to show it.

Make the critter move

make a move function to change the critter x and y.

Make a draw function to clear the screen and draw the critter at the new position.

make a wrap-around world

set a world width and a world height

if the critter is past the left edge (x<0) move it to the right edge

if the critter is past the right edge (x>worldWidth) move it to the left edge

if the critter is past the top edge (y<0) move it to the bottom edge

if the critter is past the bottom edge (y>worldHeight) move it to the top edge

give the critter some direction

add dx and dy parts to the critter

instead of adding fixed amounts to the critter position each time add the dx and dy values

change the dx and dy values a little bit each time it moves.