Add visual notifications of certain events.

[Nick B]

From Matt S:

I tend to play mobile games with the sound off (I'm either at home listening to TV/radio or on the tube listening to music/podcasts), so you need a notification for when they go off screen and die

[Nick B]

Add visual indications (screen flashing)

• Dying flashes red - this fixes Issue #9.
• New level fades in a little too
• Fade out is W.I.P.

→ <<cset be780f5230ab>>