Reasons to love Python

It let's you do twisted things like this:

waves = [[Clown, Clown, Clown],
	[Clown, Tank, Bunny, Clown],
	[Clown, Tank, Tank, Clown],
	[Clown, Tank, Tank, Bunny],
	[Tank, Tank, Tank, Clown],
	...
	]

where Clown, Tank and Bunny are the Types of the various enemies
and later...

for enemy in waves[wave]:
	enemy(xpos, ypos, 0, 0, self.target)

and it just figures it out and calls the constructor for the relevant type.