add a class just for slugs
add slug movement

the slug now moves left and right
turns around at the edges of platforms
displays correct movement animation
add dying when you touch an enemy

if the player intersects with an enemy
draw the dying animation and quit the game
player dies when they fall off screen

check if player is below the bottow of the level
kill them
add slug slime

slug has a random chance to drop slime
player dies if it touches slime
after a while slime becomes harmless and then disappears