These funky characters can be unlocked by completing the described tasks.

Unlock Ice Tea:
Suffer 50 shots to the 'junk' (this area is clearly described in the game).

Unlock The Dude:
Play the bowling Multi-Player game 12 times.

Unlock Ed the Cow:
On the Downtown stage blow up the cow with the grab-bomb box 12 times.

When you score at least 1,500,000 points in a single shot in PAINdemonium mode the Aftermanth mode becomes an avaialable option. Aftermath mode is a free for all where you try and rack up a hi-score to compete on the leaderboard.

The following trophies become unlocked when the corresponding task has been completed in the game. Some are easier than others to obtain.

Unlock 500k Points Trophy:
Score at least 500,000 points.

Unlock 2 Mil Points Trophy:
Score at least 2,000,000 points.

Unlock 3 Mil Points Trophy:
Score at least 3,000,000 points.

Unlock 500k Pain Trophy:
Get a Pain Score of at least 500,000.

Unlock 1.5 Mil Pain Trophy:
Get a Pain Score of at least 1,500,000.

Unlock 20X Combo Trophy:
Get a combo bar of 20.

Unlock Blue Hair Trophy:
Grab the old lady.

Unlock Bowling Ball! Trophy:
Grab the Bowling Ball.

Unlock Grab Master Trophy:
Make 1,000 Grabs.

Unlock King of the Jungle Trophy:
Grab a Swinging Girder.

Unlock Cross Town Trophy:
Travel 2,000 feet in one launch.

Unlock Moon Landing Trophy:
Reach an Altitude of 300,000 feet.

Unlock Frequent Flyer Trophy:
Travel over 200 miles.

Unlock Sick and Twisted Trophy:
Make 500 Grabs.

Unlock Take A Ride Trophy:
Grab the Train.