I know it's very very early for April fools,
but if I make the suggestion now, everyone but a few people (I'm looking at you, Splash Damage), will have forgotten it by then.
Right, so here's the idea:
Replace every single sound file in the game with a sound file of MissMurder mimicking the replaced sound.
PS: I'm willing to pass on 2 months of updates for this
PPS: I'm also willing to sacrifice 1/3 of my soul for it