Level design prototype

[ironkayman]

Reconsider and expand current level logic as of current one:

name = "1"

[[waves]]
# alien types present of a level
spawns = ['dummy_ufo', 'castle_wall_sontra']
# randomly generate enemies but their total health
# should not get bigger than that number
total_enemy_health = 400
# score/experince from killed aliens required to pass this wave
pass_score = 30
# interval in seconds before density_multplier increase
interval = 30
# how many enemies and their speed will increase at next interval
density_multiplier = 1.7

# enemy_size_restrictions