Anilrgowda

Battle Of The Gods:
Play "Praise you", "Rubberneckin", and "Addicted to Bass" all under the hard difficulty setting. The player with the biggest score out of those three rounds combined wins. Note: This requires the bonus tracks.

Bonus tracks:
Play all twenty tracks to unlock a further five tracks to keep you occupied. The bonus tracks are Gotta Get Through This (Daniel Bedingfield), Keep On Moving (Five), Aserjere (Las Ketchup), Rubberneckin (Elvis Presley), and Addicted To Bass (Puretone).

Dance Like Hell:
Play "Addicted To Bass" in master mode. You will not last long, but the idea is to see how long you last.

Danceathon:
Play all twenty five songs in a row on any mode. The player with the biggest score out of all those rounds combined wins. Note: This requires the bonus tracks.

Drybone:
Set up calorie mode and burn at least 10, 15 or 20 calories.

Goldie Oldie (in order of age):
Play "Dance To The Music", "Jungle Boogie", "YMCA", "We Are Family", and "Let"s Groove".

Home-made games:
The following is a list of fun games you can invent to keep the groove going. They are best played with two or more players.

Master level difficulty:
To unlock as master difficulty, get an A rank in one of the tracks. You will then have a new difficulty level. It is (as far as I can tell) exactly like hard mode but with less warning when the heads will appear.

Pain In The Neck:
Play "Praise You" in master mode.

Perfection:
The person with the most amount of perfects wins; points are irrelevant.

Score big:
To score big, play perfection in the tournament mode against another player. This will hopefully improve your timing.

Track 21-25:
Complete tracks 1-20 all the way through on any mode.