The white, pearly gates of Heaven. Little cherubs prancing peacefully, a seraph or two floats by, souls laugh in happy bliss...

The calm is disturbed.

Like a giant maw of death, a blood-red steaming gash appears in the fabric of Heaven, form whence steps forth a man. The green blood of a thousand hell spawn on his pudgy form, his glasses cracked by demon-fire. A rusty chainsaw in his hands.

Looking around: "Aha, so this must be the bonus level"