Bully

Unlock Girlfriends:
Complete the following challenge to unlock the indicated girlfriend:

Unlock Beatrice - Finish "That Bitch" challenge in Chapter 1.
Unlock Lola - Finish "The Tenements" challenge in Chapter 3.
Unlock Mandy - Finish "Discretion Assured" challenge in Chapter 4.
Unlock Pinky - Finish "Carnival Date" challenge in Chapter 2.
Unlock Zoe - Finish "Smash It Up" challenge in Chapter 5.

Note: Kiss your girlfriend for additional health.

Jimmy's room decorations:
Complete the following challenge or chapter to unlock the indicated decorations:

Kill all gnomes - Unlock Gnome
Finish the Beach Rumble" challenge - Unlock Trophy (on windowsill)
Finish the "Weed Killer" challenge in Chapter 2 - Unlock Venus Flytrap Head
Finish the "Total Mayhem" challenge - Unlock Bullworth Golden Shield
Finish the "That Bitch" challenge in Chapter 1 - Unlock Picture of Beatrice