My friend tries to get me to like halo what should i do?

On top of that he also talks about building 200,000 mile long space cruisers and star fighters capable of glassing countries and hacking other air crafts controls. And also taking over the world and nanites capable of regenerating lost body limbs and making people with them immune to damage. What should i do without being to rude and ruining my friendship? This is all based off of halo 3 and the other games mind you.