The first line is a joke about Halo. In that game, most of the rooms looked exactly alike. And the Covenant were the alien bad guys. If you still don't get it, just go play some Halo.
Metroid, Samus Aran, Space Pirates, and all that other stuff are properties of Nintendo. Contra is a property of Konami. All other characters are property of their respective owners. Pretty much everything else is property of me, unless specifically noted otherwise.