Snowball fight:
Bring all the cousins to the snowy island. Release them and press "A" to make a snowball. Throw it with "A" at a cousin, then dodge when they throw one back. If the snowball hits another cousin, they will join in and try to hit you. If you keep dodging, they will keep throwing snowballs until either you are hit or nobody is hit.
Formal Outfit:
Collect 100% of the items to unlock the Formal Outfit present.
Unlock endless mode:
Get 100 points on a level to unlock endless mode for it. You will than be able to play that level with no time limit.
Achievements:
| Achievements | How to Unlock |
| Manic Roller (20 points) | Running into walls will destroy your Katamari. |
| Quick Turner (10 points) | Use Quick Turn to your advantage. |
| Speedy Roller (10 points) | Zip through the course with Dash. |
| Responsible Roller (30 points) | Roll through the course without bumping into any objects. |
| Non-stop Roller (30 points) | Roll through the course without stopping once. |
| Online Roller (5 points) | Play online. |
| Frequent Online Roller (10 points) | Play online 10 times. |
| Resident Online Roller (40 points) | Play online 50 times. |
| 100 Cookies (5 points) | Obtain 100 Cookies. |
| 1,000 Cookies (40 points) | Obtain 1,000 Cookies. |
| 10 Presents (5 points) | Collect 10 Presents. |
| 20 Presents (10 points) | Collect 20 Presents. |
| 30 Presents (20 points) | Collect 30 Presents. |
| All Presents (80 points) | Download stages and collect all Presents. |
| 10 Cousins (5 points) | Find 10 Cousins. |
| 20 Cousins (10 points) | Find 20 Cousins. |
| 30 Cousins (20 points) | Find 30 Cousins. |
| 40 Cousins (40 points) | Find 40 Cousins. |
| All Cousins (80 points) | Download stages and find all Cousins. |
| Collection 20% (5 points) | Roll up 20% of the Collection. |
| Collection 40% (10 points) | Roll up 40% of the Collection. |
| Collection 60% (20 points) | Roll up 60% of the Collection. |
| Collection 80% (40 points) | Roll up 80% of the Collection. |
| Request x 3 (5 points) | Complete 3 Requests. |
| Request x 6 (5 points) | Complete 6 Requests. |
| Request x 9 (20 points) | Complete 9 Requests. |
| All Requests (60 points) | Complete all Requests. |
| Mini Katamari (5 points) | Make a Katamari that's 30cm or more. |
| Small Katamari (5 points) | Make a Katamari that's 1m or more. |
| Sorta Big Katamari (5 points) | Make a Katamari that's 5m or more. |
| Big Katamari (10 points) | Make a Katamari that's 30m or more. |
| Jumbo Katamari (20 points) | Make a Katamari that's 500m or more. |
| Colossal Katamari (60 points) | Make a Katamari that's 10,000km or more. |
| Astronomic Katamari (90 points) | Download stages and make a Katamari over 1,500,000km. |
