Hear me out... more L4D Survivors!
We've all noticed the Left 4 Dead cosmetics and charms. Personally, I absolutely adore the Left 4 Dead franchise and seeing Bill as an actual survivor was AWESOME! Then It got me thinking... currently, four survivors can dress up as the L4D survivors, why don't they make outfits for lets say Felix, he wears a slick suit... So does Nick, maybe have Adam dress up as Louis or Coach. This seems like it would be very awesome especially since they had half the team already.
I also think a Left 4 Dead Chapter would be amazing too, have the tank as the killer, maybe make the terror radius INFINITE so that dreadful music plays EVERYWHERE! Snice the tank could be heard for anywhere, I though adding meaty footsteps (Like he is in L4D) when he's near would be petrifying. Like a Huntress' terror radius, he will have an inner terror radius where you can hear him approaching...