Room. Room is a cool area in which even the best heroes can conveniently feel themselves lonely and forgetten. Possibly this is why they are enjoying the crossover moments a lot. Just have a look at Samus Aran from"Metroid" and Master Chief from "Halo" - these two have started fucking even before taking any of their garments off! And even though it is just one animated scene you don't have to be the hardcore fan to enjoy it for fairly time!