Disney's The Little Mermaid: Ariel’s Undersea Adventure doesn’t follow a specific storyline. Instead, gameplay takes more of a free form approach, allowing you to explore levels and find treasures or perform other activities. Most of the gameplay tasks take the form of short mini-games that have you using all of the DS’s functions in a variety of ways.
For example, before a treasure can be placed in Ariel’s treasure trove, it must first be cleaned up. You begin by using the touch screen to scare away hermit crabs and remove barnacles. Then you clear away dirt by blowing in the microphone. Finally, it is back to the touch screen to polish up your treasure. This is only the beginning as other mini-games have you blowing bubbles of certain sizes or even singing (in tune no less) in order to unlock chests. While some of the games will definitely leave you winded or straining (especially the bubble blowing and singing), none of the functions feel forced.
From a pure gameplay standpoint, Undersea Adventure has a few rough spots -- the main one being the roaming aspect. There is an attempt to inject a bit of plot into the game, but in the end, it is forgettable. Most of the time it feels like you are simply floating around looking for items. On some level, I’m sure this was the designer’s purpose, but at the same time, the unguided scavenger hunt can become dull after you’ve just finished polishing another piece of treasure or singing open another lock.
When collecting items starts to become too tiresome, you can always head back to the top of the sea slide. Here you can visit with Sebastian and help with rehearsals, or arrange Ariel’s treasures in her grotto. Treasures can also be used in tandem with her magic pearl and unlock clips from the movie.