Kelly asked me if I could share some ideas about starting points for finding out the info and details necessary for putting together your Playlist assignment. Although we unfortunately can't always play every game at the early stages of putting together a list or collection (especially when dealing with commercial and console games), there are still many resources available for finding out about a game's contents.
1) Academic articles and reviews (there are surprisingly few of these out there on kids' games, but there are some, and can be a very valuable source of info when you find one). Example: Well-Played, Game Studies Journal
2) Reviews and postmortems published in the press - particularly within publications specific to gaming. Example Kotaku and Gamasutra.
3) Reviews and articles published on media watchgroups & non-profits. Examples: Common Sense Media and Children's Technology Review
4) Fan reviews and ratings (Metacritic is a great place to look for these)
5) Trailers and promotional materials produced by the game companies or media (Youtube)
6) "Walkthroughs" posted by players (usually unedited, full video coverage of the game being played - often covers a game in its entirety).
7) Demos - many games have small excerpts available for free download. For instance, Steam includes a small selection - game companies often provide downloadable demos as part of their promotion of the games.
Ideally, once a preliminary list has been produced, the games themselves could then be acquired for firsthand exploration and testing.
I've included links to a number of potentially useful sites under "Resources" on the righthand navigation bar of this site.