Tyranid improvement.

Hello. First of all Iove this game. Buut after having to deal with Chaos Tyranids starts to feel a little underwhelming. So here is an idea: A new game (Difficulty?) mode where the tyranids start attacking as soon as you land on a mission non stop until the end of the mission. They're a swarm after all and they are smart enough to see the Thunderhawk. And we make enough noise to attract more and more. An endless wave of enemies if you will.