IGN found the title to be "awesome," and was very impressed by the diversity in the game. Even though it's called Crosswords DS, there's more to it than crossword puzzles. The game also includes word searches and anagrams. According to the site, the controls are very intuitive, and even easier to understand because of the great interface.
Game|Life also enjoyed the software, finding the anagram mode to be even more addictive than the crosswords themselves. From what we can tell by Game|Life's comments, the anagram puzzles look almost identical to those in the online game Text Twist, which this blogger can confirm to be the computer equivalent of crack cocaine.
GoNintendo describes this title as a "must-have" if you like crosswords. RMC reported that the puzzles are challenging (although the ones shown in the gallery must be from the "easy" setting), so don't worry about a dumbed-down experience.
Also, don't be put off by the game's lame box art -- it seems like this title is definitely something to look forward to!
Gallery: Crosswords DS
Read: IGN's impressions
Read: Game|Life's impressions
Read: GoNintendo's impressions