CheatOgre.com: ESPN International Winter Sports 2002

Bear costume
Win all gold medals in the men's events in championship mode. Press L or R at the character selection screen to access the costume. Note: Using this costume will disqualify you from winning medals or setting records.

Penguin costume
Win all gold medals in the women's events in championship mode. Press L or R at the character selection screen to access the costume. Note: Using this costume will disqualify you from winning medals or setting records.

Robot costume
Win all gold medals in the men's and women's events in trial mode. Press L or R at the character selection screen to access the costume. Note: Using this costume will disqualify you from winning medals or setting records.