Eurogamer writes: "Not unlike Mario Kart Wii and its boost mechanics, LocoRoco 2 appears to be after a record for the most collectibles in a platform game ever. There are berries and pickories scattered around like Mario's coins and Sonic's rings. There are musical notes hidden in plants and awarded for clearing out dark clouds, and when you've gathered a hundred these level-up the stage you're on so that you can gather berries and pickories with greater ease.
There are stamps, which can be arranged into pretty patterns or matched against silhouettes. There are the cheerful little Mui Mui silhouette men, who, once collected, disappear to the Mui Mui House, which you can play with in a mini-game. There are Mui Mui House parts, so you can make some furniture, and sometimes there are Mui Mui weapon parts, so you can defend the house from the evil Bui Bui bombers. And of course there are the red flowers, each of which adds another smiling LocoRoco blob to your seamless, ball-shaped mass of heroes."