Place in plugins server and use
Config.yml :
creeper-spawn:
spawn-radius-per-player: 64
spawn-radius-per-player-min: 16
spawn-radius-per-player-y: 32
points-per-second:
land: 5
air: 1
sea: 2
lava: 1
ground: 0
max-generation-time: 20
limit-multiplier: 1.2