Make the game harder — ProtectHeart Steam update #738543

- Turtles will now have small health increases as levels increase - Blue blimps health updated 25 -> 20 + damage * 10 - Red blimps health updated 100 -> 100 + damage * 65 - Grey/Black blimps health updated 600 -> 250 + damage * 500 - Fighter Jet health updated 800 -> 1000 + damage * 650 - Turtles can now appear faster naturally 0.8s -> 0.45s - Slightly increased the volume of elimination sfx