9. The Bullet Time Meter Is Two Stacked Bullets - Max Payne 2: The Fall Of Max Payne
The Max Payne games may be orgiastic, John Woo-inspired bloodbaths, but that doesn't mean they're totally bereft of subtlety.
The second game introduces a few nips and tucks to the series' user interface, such as slyly redesigning the distinctive hour glass meter used to measure the player's remaining bullet time.
While in the first game it more or less looked like an hourglass, its more elongated design in the sequel confirms it's actually supposed to be two bullets stacked on top of each other, tip to tip.
If you're feeling a bit silly for having missed such a seemingly obvious detail, remember that the Max Payne games rarely give players more than a moment to catch their breath between chaotic gunfights.